Toggle Side Panel

Shopping Cart

No products in the basket.

Shopping Cart

No products in the basket.

Close search
Home / DTC / P1611 — Serial Communicating Link Transmission Control Module

P1611 — Serial Communicating Link Transmission Control Module

Detailed page for trouble code P1611.

35,619codes
59brands
11,925generic
23,694specific
All codes P-codes (Powertrain) B-codes (Body) C-codes (Chassis) U-codes (Network/User) Tesla Alerts
Reset
Code

P1611

BMW P — Powertrain

Serial Communicating Link Transmission Control Module

Brand: BMW
Type: P — Powertrain
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Open or shorted CAN/serial communication wires
  • Corroded/damaged connectors at the TCM or junctions
  • Blown fuse or faulty relay supplying TCM power
  • Weak battery or poor chassis ground causing module reset
  • Faulty or unresponsive Transmission Control Module (TCM)
  • Faulty engine/vehicle control module (ECM/BCM) that bridges the bus

Symptoms

  • Check Engine / Transmission warning lamp illuminated
  • Transmission enters limp/torque‑limited mode or won’t shift properly
  • No TCM present or no response when scanned with diagnostic tool
  • Erratic gear selection or fixed gear/lockup behavior
  • Intermittent loss of communication messages on scanner live data
  • Related instrument cluster or speedometer faults if bus messages missing

What to check

  • Obtain and record all stored and pending codes from all modules (scan tool)
  • Confirm whether TCM is present on the diagnostic network (module list)
  • Check battery voltage and charge state, test while cranking and with ignition on (should be stable)
  • Inspect fuses/relays for TCM power and main vehicle bus fuses
  • Visually inspect TCM connectors and wiring for corrosion, bent pins or damage
  • Measure power and ground at the TCM connector with ignition ON

Signal parameters

  • Typical CAN bus idle voltages: CAN‑H and CAN‑L ≈2.5 V each (recessive); dominant state creates ~2 V differential (CAN‑H higher, CAN‑L lower) — verify with scope
  • Expected termination: ~60 Ω measured between CAN‑H and CAN‑L (two 120 Ω resistors in parallel)
  • If vehicle uses single‑wire serial (K‑line) consult BMW repair manual for expected idle levels and timing — use manufacturer tool for protocol check

Diagnostic algorithm

  1. Read and save all DTCs from all modules; note time stamps and freeze data. 2) Confirm whether the TCM responds to the scan tool and whether other modules report communication faults. 3) Verify battery voltage and charging system; recharge or replace if low. 4) Check/replace relevant fuses and relays for TCM and vehicle data bus. 5) Visually inspect and clean TCM connector and ground points; repair damaged pins/wires. 6) Measure power and ground at the TCM connector; repair any supply faults. 7) Measure termination resistance and use a scope or CAN‑bus tool to observe message traffic and verify proper recessive/dominant levels. 8) Isolate sections of the network (disconnect non‑essential nodes) to find the failing node if bus is shorted. 9) If wiring and bus signals are correct but communication still fails, verify software/coding and reflash modules per manufacturer procedure. 10) Replace TCM only after confirming wiring, power/ground, and bus integrity; program/recode new module and recheck. 11) Clear codes and perform road test; re-scan to confirm repair.
  2. similar_codes([

Likely causes

  • Damaged/loose connector or wiring to the TCM
  • Power or ground fault at the TCM (fuse, relay, battery)
  • CAN bus fault (short to battery/ground or open, missing termination)
  • Faulty TCM hardware or corrupted firmware
  • ECM/other network module not forwarding messages

Fault status

⚠️ Status
TCM not communicating on serial link (communication lost/invalid). Check wiring, power/grounds, CAN/serial bus, and module connectivity.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 1.5-3.0 hours

Similar codes

U0100 U0101 U0073 U0121 P0700
Repair manuals

Manual library for BMW

479

Browse 479 BMW manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.

BMW

Your experience will help others
+100 karma for a short comment :)
Keep it short and practical. Up to 500 characters.
Send to email
Code

P1611

BUICK P — Powertrain

Loss Of CVRTD Serial Data

Brand: BUICK
Type: P — Powertrain
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Open or shorted CAN/serial communication wires
  • Corroded/damaged connectors at the TCM or junctions
  • Blown fuse or faulty relay supplying TCM power
  • Weak battery or poor chassis ground causing module reset
  • Faulty or unresponsive Transmission Control Module (TCM)
  • Faulty engine/vehicle control module (ECM/BCM) that bridges the bus

Symptoms

  • Check Engine / Transmission warning lamp illuminated
  • Transmission enters limp/torque‑limited mode or won’t shift properly
  • No TCM present or no response when scanned with diagnostic tool
  • Erratic gear selection or fixed gear/lockup behavior
  • Intermittent loss of communication messages on scanner live data
  • Related instrument cluster or speedometer faults if bus messages missing

What to check

  • Obtain and record all stored and pending codes from all modules (scan tool)
  • Confirm whether TCM is present on the diagnostic network (module list)
  • Check battery voltage and charge state, test while cranking and with ignition on (should be stable)
  • Inspect fuses/relays for TCM power and main vehicle bus fuses
  • Visually inspect TCM connectors and wiring for corrosion, bent pins or damage
  • Measure power and ground at the TCM connector with ignition ON

Signal parameters

  • Typical CAN bus idle voltages: CAN‑H and CAN‑L ≈2.5 V each (recessive); dominant state creates ~2 V differential (CAN‑H higher, CAN‑L lower) — verify with scope
  • Expected termination: ~60 Ω measured between CAN‑H and CAN‑L (two 120 Ω resistors in parallel)
  • If vehicle uses single‑wire serial (K‑line) consult BMW repair manual for expected idle levels and timing — use manufacturer tool for protocol check

Diagnostic algorithm

  1. Read and save all DTCs from all modules; note time stamps and freeze data. 2) Confirm whether the TCM responds to the scan tool and whether other modules report communication faults. 3) Verify battery voltage and charging system; recharge or replace if low. 4) Check/replace relevant fuses and relays for TCM and vehicle data bus. 5) Visually inspect and clean TCM connector and ground points; repair damaged pins/wires. 6) Measure power and ground at the TCM connector; repair any supply faults. 7) Measure termination resistance and use a scope or CAN‑bus tool to observe message traffic and verify proper recessive/dominant levels. 8) Isolate sections of the network (disconnect non‑essential nodes) to find the failing node if bus is shorted. 9) If wiring and bus signals are correct but communication still fails, verify software/coding and reflash modules per manufacturer procedure. 10) Replace TCM only after confirming wiring, power/ground, and bus integrity; program/recode new module and recheck. 11) Clear codes and perform road test; re-scan to confirm repair.
  2. similar_codes([

Likely causes

  • Damaged/loose connector or wiring to the TCM
  • Power or ground fault at the TCM (fuse, relay, battery)
  • CAN bus fault (short to battery/ground or open, missing termination)
  • Faulty TCM hardware or corrupted firmware
  • ECM/other network module not forwarding messages

Fault status

⚠️ Status
TCM not communicating on serial link (communication lost/invalid). Check wiring, power/grounds, CAN/serial bus, and module connectivity.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 1.5-3.0 hours

Similar codes

U0100 U0101 U0073 U0121 P0700
Your experience will help others
+100 karma for a short comment :)
Keep it short and practical. Up to 500 characters.
Send to email
Code

P1611

CADILLAC P — Powertrain

Loss Of CVRTD Serial Data

Brand: CADILLAC
Type: P — Powertrain
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Open or shorted CAN/serial communication wires
  • Corroded/damaged connectors at the TCM or junctions
  • Blown fuse or faulty relay supplying TCM power
  • Weak battery or poor chassis ground causing module reset
  • Faulty or unresponsive Transmission Control Module (TCM)
  • Faulty engine/vehicle control module (ECM/BCM) that bridges the bus

Symptoms

  • Check Engine / Transmission warning lamp illuminated
  • Transmission enters limp/torque‑limited mode or won’t shift properly
  • No TCM present or no response when scanned with diagnostic tool
  • Erratic gear selection or fixed gear/lockup behavior
  • Intermittent loss of communication messages on scanner live data
  • Related instrument cluster or speedometer faults if bus messages missing

What to check

  • Obtain and record all stored and pending codes from all modules (scan tool)
  • Confirm whether TCM is present on the diagnostic network (module list)
  • Check battery voltage and charge state, test while cranking and with ignition on (should be stable)
  • Inspect fuses/relays for TCM power and main vehicle bus fuses
  • Visually inspect TCM connectors and wiring for corrosion, bent pins or damage
  • Measure power and ground at the TCM connector with ignition ON

Signal parameters

  • Typical CAN bus idle voltages: CAN‑H and CAN‑L ≈2.5 V each (recessive); dominant state creates ~2 V differential (CAN‑H higher, CAN‑L lower) — verify with scope
  • Expected termination: ~60 Ω measured between CAN‑H and CAN‑L (two 120 Ω resistors in parallel)
  • If vehicle uses single‑wire serial (K‑line) consult BMW repair manual for expected idle levels and timing — use manufacturer tool for protocol check

Diagnostic algorithm

  1. Read and save all DTCs from all modules; note time stamps and freeze data. 2) Confirm whether the TCM responds to the scan tool and whether other modules report communication faults. 3) Verify battery voltage and charging system; recharge or replace if low. 4) Check/replace relevant fuses and relays for TCM and vehicle data bus. 5) Visually inspect and clean TCM connector and ground points; repair damaged pins/wires. 6) Measure power and ground at the TCM connector; repair any supply faults. 7) Measure termination resistance and use a scope or CAN‑bus tool to observe message traffic and verify proper recessive/dominant levels. 8) Isolate sections of the network (disconnect non‑essential nodes) to find the failing node if bus is shorted. 9) If wiring and bus signals are correct but communication still fails, verify software/coding and reflash modules per manufacturer procedure. 10) Replace TCM only after confirming wiring, power/ground, and bus integrity; program/recode new module and recheck. 11) Clear codes and perform road test; re-scan to confirm repair.
  2. similar_codes([

Likely causes

  • Damaged/loose connector or wiring to the TCM
  • Power or ground fault at the TCM (fuse, relay, battery)
  • CAN bus fault (short to battery/ground or open, missing termination)
  • Faulty TCM hardware or corrupted firmware
  • ECM/other network module not forwarding messages

Fault status

⚠️ Status
TCM not communicating on serial link (communication lost/invalid). Check wiring, power/grounds, CAN/serial bus, and module connectivity.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 1.5-3.0 hours

Similar codes

U0100 U0101 U0073 U0121 P0700
206

Browse 206 CADILLAC manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.

CADILLAC

Your experience will help others
+100 karma for a short comment :)
Keep it short and practical. Up to 500 characters.
Send to email
Code

P1611

CHEVROLET P — Powertrain

Loss Of CVRTD Serial Data

Brand: CHEVROLET
Type: P — Powertrain
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Open or shorted CAN/serial communication wires
  • Corroded/damaged connectors at the TCM or junctions
  • Blown fuse or faulty relay supplying TCM power
  • Weak battery or poor chassis ground causing module reset
  • Faulty or unresponsive Transmission Control Module (TCM)
  • Faulty engine/vehicle control module (ECM/BCM) that bridges the bus

Symptoms

  • Check Engine / Transmission warning lamp illuminated
  • Transmission enters limp/torque‑limited mode or won’t shift properly
  • No TCM present or no response when scanned with diagnostic tool
  • Erratic gear selection or fixed gear/lockup behavior
  • Intermittent loss of communication messages on scanner live data
  • Related instrument cluster or speedometer faults if bus messages missing

What to check

  • Obtain and record all stored and pending codes from all modules (scan tool)
  • Confirm whether TCM is present on the diagnostic network (module list)
  • Check battery voltage and charge state, test while cranking and with ignition on (should be stable)
  • Inspect fuses/relays for TCM power and main vehicle bus fuses
  • Visually inspect TCM connectors and wiring for corrosion, bent pins or damage
  • Measure power and ground at the TCM connector with ignition ON

Signal parameters

  • Typical CAN bus idle voltages: CAN‑H and CAN‑L ≈2.5 V each (recessive); dominant state creates ~2 V differential (CAN‑H higher, CAN‑L lower) — verify with scope
  • Expected termination: ~60 Ω measured between CAN‑H and CAN‑L (two 120 Ω resistors in parallel)
  • If vehicle uses single‑wire serial (K‑line) consult BMW repair manual for expected idle levels and timing — use manufacturer tool for protocol check

Diagnostic algorithm

  1. Read and save all DTCs from all modules; note time stamps and freeze data. 2) Confirm whether the TCM responds to the scan tool and whether other modules report communication faults. 3) Verify battery voltage and charging system; recharge or replace if low. 4) Check/replace relevant fuses and relays for TCM and vehicle data bus. 5) Visually inspect and clean TCM connector and ground points; repair damaged pins/wires. 6) Measure power and ground at the TCM connector; repair any supply faults. 7) Measure termination resistance and use a scope or CAN‑bus tool to observe message traffic and verify proper recessive/dominant levels. 8) Isolate sections of the network (disconnect non‑essential nodes) to find the failing node if bus is shorted. 9) If wiring and bus signals are correct but communication still fails, verify software/coding and reflash modules per manufacturer procedure. 10) Replace TCM only after confirming wiring, power/ground, and bus integrity; program/recode new module and recheck. 11) Clear codes and perform road test; re-scan to confirm repair.
  2. similar_codes([

Likely causes

  • Damaged/loose connector or wiring to the TCM
  • Power or ground fault at the TCM (fuse, relay, battery)
  • CAN bus fault (short to battery/ground or open, missing termination)
  • Faulty TCM hardware or corrupted firmware
  • ECM/other network module not forwarding messages

Fault status

⚠️ Status
TCM not communicating on serial link (communication lost/invalid). Check wiring, power/grounds, CAN/serial bus, and module connectivity.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 1.5-3.0 hours

Similar codes

U0100 U0101 U0073 U0121 P0700
917

Browse 917 CHEVROLET manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.

CHEVROLET

Your experience will help others
+100 karma for a short comment :)
Keep it short and practical. Up to 500 characters.
Send to email
Code

P1611

DAEWOO P — Powertrain

Main relay crct (open/gnd sht)

Brand: DAEWOO
Type: P — Powertrain
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Open or shorted CAN/serial communication wires
  • Corroded/damaged connectors at the TCM or junctions
  • Blown fuse or faulty relay supplying TCM power
  • Weak battery or poor chassis ground causing module reset
  • Faulty or unresponsive Transmission Control Module (TCM)
  • Faulty engine/vehicle control module (ECM/BCM) that bridges the bus

Symptoms

  • Check Engine / Transmission warning lamp illuminated
  • Transmission enters limp/torque‑limited mode or won’t shift properly
  • No TCM present or no response when scanned with diagnostic tool
  • Erratic gear selection or fixed gear/lockup behavior
  • Intermittent loss of communication messages on scanner live data
  • Related instrument cluster or speedometer faults if bus messages missing

What to check

  • Obtain and record all stored and pending codes from all modules (scan tool)
  • Confirm whether TCM is present on the diagnostic network (module list)
  • Check battery voltage and charge state, test while cranking and with ignition on (should be stable)
  • Inspect fuses/relays for TCM power and main vehicle bus fuses
  • Visually inspect TCM connectors and wiring for corrosion, bent pins or damage
  • Measure power and ground at the TCM connector with ignition ON

Signal parameters

  • Typical CAN bus idle voltages: CAN‑H and CAN‑L ≈2.5 V each (recessive); dominant state creates ~2 V differential (CAN‑H higher, CAN‑L lower) — verify with scope
  • Expected termination: ~60 Ω measured between CAN‑H and CAN‑L (two 120 Ω resistors in parallel)
  • If vehicle uses single‑wire serial (K‑line) consult BMW repair manual for expected idle levels and timing — use manufacturer tool for protocol check

Diagnostic algorithm

  1. Read and save all DTCs from all modules; note time stamps and freeze data. 2) Confirm whether the TCM responds to the scan tool and whether other modules report communication faults. 3) Verify battery voltage and charging system; recharge or replace if low. 4) Check/replace relevant fuses and relays for TCM and vehicle data bus. 5) Visually inspect and clean TCM connector and ground points; repair damaged pins/wires. 6) Measure power and ground at the TCM connector; repair any supply faults. 7) Measure termination resistance and use a scope or CAN‑bus tool to observe message traffic and verify proper recessive/dominant levels. 8) Isolate sections of the network (disconnect non‑essential nodes) to find the failing node if bus is shorted. 9) If wiring and bus signals are correct but communication still fails, verify software/coding and reflash modules per manufacturer procedure. 10) Replace TCM only after confirming wiring, power/ground, and bus integrity; program/recode new module and recheck. 11) Clear codes and perform road test; re-scan to confirm repair.
  2. similar_codes([

Likely causes

  • Damaged/loose connector or wiring to the TCM
  • Power or ground fault at the TCM (fuse, relay, battery)
  • CAN bus fault (short to battery/ground or open, missing termination)
  • Faulty TCM hardware or corrupted firmware
  • ECM/other network module not forwarding messages

Fault status

⚠️ Status
TCM not communicating on serial link (communication lost/invalid). Check wiring, power/grounds, CAN/serial bus, and module connectivity.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 1.5-3.0 hours

Similar codes

U0100 U0101 U0073 U0121 P0700
Repair manuals

Manual library for DAEWOO

75

Browse 75 DAEWOO manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.

DAEWOO

Your experience will help others
+100 karma for a short comment :)
Keep it short and practical. Up to 500 characters.
Send to email
Code

P1611

GM P — Powertrain

Loss Of CVRTD Serial Data

Brand: GM
Type: P — Powertrain
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Open or shorted CAN/serial communication wires
  • Corroded/damaged connectors at the TCM or junctions
  • Blown fuse or faulty relay supplying TCM power
  • Weak battery or poor chassis ground causing module reset
  • Faulty or unresponsive Transmission Control Module (TCM)
  • Faulty engine/vehicle control module (ECM/BCM) that bridges the bus

Symptoms

  • Check Engine / Transmission warning lamp illuminated
  • Transmission enters limp/torque‑limited mode or won’t shift properly
  • No TCM present or no response when scanned with diagnostic tool
  • Erratic gear selection or fixed gear/lockup behavior
  • Intermittent loss of communication messages on scanner live data
  • Related instrument cluster or speedometer faults if bus messages missing

What to check

  • Obtain and record all stored and pending codes from all modules (scan tool)
  • Confirm whether TCM is present on the diagnostic network (module list)
  • Check battery voltage and charge state, test while cranking and with ignition on (should be stable)
  • Inspect fuses/relays for TCM power and main vehicle bus fuses
  • Visually inspect TCM connectors and wiring for corrosion, bent pins or damage
  • Measure power and ground at the TCM connector with ignition ON

Signal parameters

  • Typical CAN bus idle voltages: CAN‑H and CAN‑L ≈2.5 V each (recessive); dominant state creates ~2 V differential (CAN‑H higher, CAN‑L lower) — verify with scope
  • Expected termination: ~60 Ω measured between CAN‑H and CAN‑L (two 120 Ω resistors in parallel)
  • If vehicle uses single‑wire serial (K‑line) consult BMW repair manual for expected idle levels and timing — use manufacturer tool for protocol check

Diagnostic algorithm

  1. Read and save all DTCs from all modules; note time stamps and freeze data. 2) Confirm whether the TCM responds to the scan tool and whether other modules report communication faults. 3) Verify battery voltage and charging system; recharge or replace if low. 4) Check/replace relevant fuses and relays for TCM and vehicle data bus. 5) Visually inspect and clean TCM connector and ground points; repair damaged pins/wires. 6) Measure power and ground at the TCM connector; repair any supply faults. 7) Measure termination resistance and use a scope or CAN‑bus tool to observe message traffic and verify proper recessive/dominant levels. 8) Isolate sections of the network (disconnect non‑essential nodes) to find the failing node if bus is shorted. 9) If wiring and bus signals are correct but communication still fails, verify software/coding and reflash modules per manufacturer procedure. 10) Replace TCM only after confirming wiring, power/ground, and bus integrity; program/recode new module and recheck. 11) Clear codes and perform road test; re-scan to confirm repair.
  2. similar_codes([

Likely causes

  • Damaged/loose connector or wiring to the TCM
  • Power or ground fault at the TCM (fuse, relay, battery)
  • CAN bus fault (short to battery/ground or open, missing termination)
  • Faulty TCM hardware or corrupted firmware
  • ECM/other network module not forwarding messages

Fault status

⚠️ Status
TCM not communicating on serial link (communication lost/invalid). Check wiring, power/grounds, CAN/serial bus, and module connectivity.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 1.5-3.0 hours

Similar codes

U0100 U0101 U0073 U0121 P0700
Your experience will help others
+100 karma for a short comment :)
Keep it short and practical. Up to 500 characters.
Send to email
Code

P1611

GMC P — Powertrain

Loss Of CVRTD Serial Data

Brand: GMC
Type: P — Powertrain
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Open or shorted CAN/serial communication wires
  • Corroded/damaged connectors at the TCM or junctions
  • Blown fuse or faulty relay supplying TCM power
  • Weak battery or poor chassis ground causing module reset
  • Faulty or unresponsive Transmission Control Module (TCM)
  • Faulty engine/vehicle control module (ECM/BCM) that bridges the bus

Symptoms

  • Check Engine / Transmission warning lamp illuminated
  • Transmission enters limp/torque‑limited mode or won’t shift properly
  • No TCM present or no response when scanned with diagnostic tool
  • Erratic gear selection or fixed gear/lockup behavior
  • Intermittent loss of communication messages on scanner live data
  • Related instrument cluster or speedometer faults if bus messages missing

What to check

  • Obtain and record all stored and pending codes from all modules (scan tool)
  • Confirm whether TCM is present on the diagnostic network (module list)
  • Check battery voltage and charge state, test while cranking and with ignition on (should be stable)
  • Inspect fuses/relays for TCM power and main vehicle bus fuses
  • Visually inspect TCM connectors and wiring for corrosion, bent pins or damage
  • Measure power and ground at the TCM connector with ignition ON

Signal parameters

  • Typical CAN bus idle voltages: CAN‑H and CAN‑L ≈2.5 V each (recessive); dominant state creates ~2 V differential (CAN‑H higher, CAN‑L lower) — verify with scope
  • Expected termination: ~60 Ω measured between CAN‑H and CAN‑L (two 120 Ω resistors in parallel)
  • If vehicle uses single‑wire serial (K‑line) consult BMW repair manual for expected idle levels and timing — use manufacturer tool for protocol check

Diagnostic algorithm

  1. Read and save all DTCs from all modules; note time stamps and freeze data. 2) Confirm whether the TCM responds to the scan tool and whether other modules report communication faults. 3) Verify battery voltage and charging system; recharge or replace if low. 4) Check/replace relevant fuses and relays for TCM and vehicle data bus. 5) Visually inspect and clean TCM connector and ground points; repair damaged pins/wires. 6) Measure power and ground at the TCM connector; repair any supply faults. 7) Measure termination resistance and use a scope or CAN‑bus tool to observe message traffic and verify proper recessive/dominant levels. 8) Isolate sections of the network (disconnect non‑essential nodes) to find the failing node if bus is shorted. 9) If wiring and bus signals are correct but communication still fails, verify software/coding and reflash modules per manufacturer procedure. 10) Replace TCM only after confirming wiring, power/ground, and bus integrity; program/recode new module and recheck. 11) Clear codes and perform road test; re-scan to confirm repair.
  2. similar_codes([

Likely causes

  • Damaged/loose connector or wiring to the TCM
  • Power or ground fault at the TCM (fuse, relay, battery)
  • CAN bus fault (short to battery/ground or open, missing termination)
  • Faulty TCM hardware or corrupted firmware
  • ECM/other network module not forwarding messages

Fault status

⚠️ Status
TCM not communicating on serial link (communication lost/invalid). Check wiring, power/grounds, CAN/serial bus, and module connectivity.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 1.5-3.0 hours

Similar codes

U0100 U0101 U0073 U0121 P0700
Your experience will help others
+100 karma for a short comment :)
Keep it short and practical. Up to 500 characters.
Send to email
Code

P1611

HUMMER P — Powertrain

Loss of CVRTD Serial Data

Brand: HUMMER
Type: P — Powertrain
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Open or shorted CAN/serial communication wires
  • Corroded/damaged connectors at the TCM or junctions
  • Blown fuse or faulty relay supplying TCM power
  • Weak battery or poor chassis ground causing module reset
  • Faulty or unresponsive Transmission Control Module (TCM)
  • Faulty engine/vehicle control module (ECM/BCM) that bridges the bus

Symptoms

  • Check Engine / Transmission warning lamp illuminated
  • Transmission enters limp/torque‑limited mode or won’t shift properly
  • No TCM present or no response when scanned with diagnostic tool
  • Erratic gear selection or fixed gear/lockup behavior
  • Intermittent loss of communication messages on scanner live data
  • Related instrument cluster or speedometer faults if bus messages missing

What to check

  • Obtain and record all stored and pending codes from all modules (scan tool)
  • Confirm whether TCM is present on the diagnostic network (module list)
  • Check battery voltage and charge state, test while cranking and with ignition on (should be stable)
  • Inspect fuses/relays for TCM power and main vehicle bus fuses
  • Visually inspect TCM connectors and wiring for corrosion, bent pins or damage
  • Measure power and ground at the TCM connector with ignition ON

Signal parameters

  • Typical CAN bus idle voltages: CAN‑H and CAN‑L ≈2.5 V each (recessive); dominant state creates ~2 V differential (CAN‑H higher, CAN‑L lower) — verify with scope
  • Expected termination: ~60 Ω measured between CAN‑H and CAN‑L (two 120 Ω resistors in parallel)
  • If vehicle uses single‑wire serial (K‑line) consult BMW repair manual for expected idle levels and timing — use manufacturer tool for protocol check

Diagnostic algorithm

  1. Read and save all DTCs from all modules; note time stamps and freeze data. 2) Confirm whether the TCM responds to the scan tool and whether other modules report communication faults. 3) Verify battery voltage and charging system; recharge or replace if low. 4) Check/replace relevant fuses and relays for TCM and vehicle data bus. 5) Visually inspect and clean TCM connector and ground points; repair damaged pins/wires. 6) Measure power and ground at the TCM connector; repair any supply faults. 7) Measure termination resistance and use a scope or CAN‑bus tool to observe message traffic and verify proper recessive/dominant levels. 8) Isolate sections of the network (disconnect non‑essential nodes) to find the failing node if bus is shorted. 9) If wiring and bus signals are correct but communication still fails, verify software/coding and reflash modules per manufacturer procedure. 10) Replace TCM only after confirming wiring, power/ground, and bus integrity; program/recode new module and recheck. 11) Clear codes and perform road test; re-scan to confirm repair.
  2. similar_codes([

Likely causes

  • Damaged/loose connector or wiring to the TCM
  • Power or ground fault at the TCM (fuse, relay, battery)
  • CAN bus fault (short to battery/ground or open, missing termination)
  • Faulty TCM hardware or corrupted firmware
  • ECM/other network module not forwarding messages

Fault status

⚠️ Status
TCM not communicating on serial link (communication lost/invalid). Check wiring, power/grounds, CAN/serial bus, and module connectivity.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 1.5-3.0 hours

Similar codes

U0100 U0101 U0073 U0121 P0700
Repair manuals

Manual library for HUMMER

138

Browse 138 HUMMER manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.

HUMMER

Your experience will help others
+100 karma for a short comment :)
Keep it short and practical. Up to 500 characters.
Send to email
Code

P1611

JAGUAR P — Powertrain

Throttle Target Malfunction 1

Brand: JAGUAR
Type: P — Powertrain
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Open or shorted CAN/serial communication wires
  • Corroded/damaged connectors at the TCM or junctions
  • Blown fuse or faulty relay supplying TCM power
  • Weak battery or poor chassis ground causing module reset
  • Faulty or unresponsive Transmission Control Module (TCM)
  • Faulty engine/vehicle control module (ECM/BCM) that bridges the bus

Symptoms

  • Check Engine / Transmission warning lamp illuminated
  • Transmission enters limp/torque‑limited mode or won’t shift properly
  • No TCM present or no response when scanned with diagnostic tool
  • Erratic gear selection or fixed gear/lockup behavior
  • Intermittent loss of communication messages on scanner live data
  • Related instrument cluster or speedometer faults if bus messages missing

What to check

  • Obtain and record all stored and pending codes from all modules (scan tool)
  • Confirm whether TCM is present on the diagnostic network (module list)
  • Check battery voltage and charge state, test while cranking and with ignition on (should be stable)
  • Inspect fuses/relays for TCM power and main vehicle bus fuses
  • Visually inspect TCM connectors and wiring for corrosion, bent pins or damage
  • Measure power and ground at the TCM connector with ignition ON

Signal parameters

  • Typical CAN bus idle voltages: CAN‑H and CAN‑L ≈2.5 V each (recessive); dominant state creates ~2 V differential (CAN‑H higher, CAN‑L lower) — verify with scope
  • Expected termination: ~60 Ω measured between CAN‑H and CAN‑L (two 120 Ω resistors in parallel)
  • If vehicle uses single‑wire serial (K‑line) consult BMW repair manual for expected idle levels and timing — use manufacturer tool for protocol check

Diagnostic algorithm

  1. Read and save all DTCs from all modules; note time stamps and freeze data. 2) Confirm whether the TCM responds to the scan tool and whether other modules report communication faults. 3) Verify battery voltage and charging system; recharge or replace if low. 4) Check/replace relevant fuses and relays for TCM and vehicle data bus. 5) Visually inspect and clean TCM connector and ground points; repair damaged pins/wires. 6) Measure power and ground at the TCM connector; repair any supply faults. 7) Measure termination resistance and use a scope or CAN‑bus tool to observe message traffic and verify proper recessive/dominant levels. 8) Isolate sections of the network (disconnect non‑essential nodes) to find the failing node if bus is shorted. 9) If wiring and bus signals are correct but communication still fails, verify software/coding and reflash modules per manufacturer procedure. 10) Replace TCM only after confirming wiring, power/ground, and bus integrity; program/recode new module and recheck. 11) Clear codes and perform road test; re-scan to confirm repair.
  2. similar_codes([

Likely causes

  • Damaged/loose connector or wiring to the TCM
  • Power or ground fault at the TCM (fuse, relay, battery)
  • CAN bus fault (short to battery/ground or open, missing termination)
  • Faulty TCM hardware or corrupted firmware
  • ECM/other network module not forwarding messages

Fault status

⚠️ Status
TCM not communicating on serial link (communication lost/invalid). Check wiring, power/grounds, CAN/serial bus, and module connectivity.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 1.5-3.0 hours

Similar codes

U0100 U0101 U0073 U0121 P0700
Your experience will help others
+100 karma for a short comment :)
Keep it short and practical. Up to 500 characters.
Send to email
Code

P1611

KIA P — Powertrain

MIL Request Circuit Voltage Low

Brand: KIA
Type: P — Powertrain
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Open or shorted CAN/serial communication wires
  • Corroded/damaged connectors at the TCM or junctions
  • Blown fuse or faulty relay supplying TCM power
  • Weak battery or poor chassis ground causing module reset
  • Faulty or unresponsive Transmission Control Module (TCM)
  • Faulty engine/vehicle control module (ECM/BCM) that bridges the bus

Symptoms

  • Check Engine / Transmission warning lamp illuminated
  • Transmission enters limp/torque‑limited mode or won’t shift properly
  • No TCM present or no response when scanned with diagnostic tool
  • Erratic gear selection or fixed gear/lockup behavior
  • Intermittent loss of communication messages on scanner live data
  • Related instrument cluster or speedometer faults if bus messages missing

What to check

  • Obtain and record all stored and pending codes from all modules (scan tool)
  • Confirm whether TCM is present on the diagnostic network (module list)
  • Check battery voltage and charge state, test while cranking and with ignition on (should be stable)
  • Inspect fuses/relays for TCM power and main vehicle bus fuses
  • Visually inspect TCM connectors and wiring for corrosion, bent pins or damage
  • Measure power and ground at the TCM connector with ignition ON

Signal parameters

  • Typical CAN bus idle voltages: CAN‑H and CAN‑L ≈2.5 V each (recessive); dominant state creates ~2 V differential (CAN‑H higher, CAN‑L lower) — verify with scope
  • Expected termination: ~60 Ω measured between CAN‑H and CAN‑L (two 120 Ω resistors in parallel)
  • If vehicle uses single‑wire serial (K‑line) consult BMW repair manual for expected idle levels and timing — use manufacturer tool for protocol check

Diagnostic algorithm

  1. Read and save all DTCs from all modules; note time stamps and freeze data. 2) Confirm whether the TCM responds to the scan tool and whether other modules report communication faults. 3) Verify battery voltage and charging system; recharge or replace if low. 4) Check/replace relevant fuses and relays for TCM and vehicle data bus. 5) Visually inspect and clean TCM connector and ground points; repair damaged pins/wires. 6) Measure power and ground at the TCM connector; repair any supply faults. 7) Measure termination resistance and use a scope or CAN‑bus tool to observe message traffic and verify proper recessive/dominant levels. 8) Isolate sections of the network (disconnect non‑essential nodes) to find the failing node if bus is shorted. 9) If wiring and bus signals are correct but communication still fails, verify software/coding and reflash modules per manufacturer procedure. 10) Replace TCM only after confirming wiring, power/ground, and bus integrity; program/recode new module and recheck. 11) Clear codes and perform road test; re-scan to confirm repair.
  2. similar_codes([

Likely causes

  • Damaged/loose connector or wiring to the TCM
  • Power or ground fault at the TCM (fuse, relay, battery)
  • CAN bus fault (short to battery/ground or open, missing termination)
  • Faulty TCM hardware or corrupted firmware
  • ECM/other network module not forwarding messages

Fault status

⚠️ Status
TCM not communicating on serial link (communication lost/invalid). Check wiring, power/grounds, CAN/serial bus, and module connectivity.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 1.5-3.0 hours

Similar codes

U0100 U0101 U0073 U0121 P0700
Repair manuals

Manual library for KIA

155

Browse 155 KIA manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.

KIA

Your experience will help others
+100 karma for a short comment :)
Keep it short and practical. Up to 500 characters.
Send to email
Code

P1611

LAND ROVER P — Powertrain

Malfunction of throttle actuator 1 Throttle malfunction

Brand: LAND ROVER
Type: P — Powertrain
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Open or shorted CAN/serial communication wires
  • Corroded/damaged connectors at the TCM or junctions
  • Blown fuse or faulty relay supplying TCM power
  • Weak battery or poor chassis ground causing module reset
  • Faulty or unresponsive Transmission Control Module (TCM)
  • Faulty engine/vehicle control module (ECM/BCM) that bridges the bus

Symptoms

  • Check Engine / Transmission warning lamp illuminated
  • Transmission enters limp/torque‑limited mode or won’t shift properly
  • No TCM present or no response when scanned with diagnostic tool
  • Erratic gear selection or fixed gear/lockup behavior
  • Intermittent loss of communication messages on scanner live data
  • Related instrument cluster or speedometer faults if bus messages missing

What to check

  • Obtain and record all stored and pending codes from all modules (scan tool)
  • Confirm whether TCM is present on the diagnostic network (module list)
  • Check battery voltage and charge state, test while cranking and with ignition on (should be stable)
  • Inspect fuses/relays for TCM power and main vehicle bus fuses
  • Visually inspect TCM connectors and wiring for corrosion, bent pins or damage
  • Measure power and ground at the TCM connector with ignition ON

Signal parameters

  • Typical CAN bus idle voltages: CAN‑H and CAN‑L ≈2.5 V each (recessive); dominant state creates ~2 V differential (CAN‑H higher, CAN‑L lower) — verify with scope
  • Expected termination: ~60 Ω measured between CAN‑H and CAN‑L (two 120 Ω resistors in parallel)
  • If vehicle uses single‑wire serial (K‑line) consult BMW repair manual for expected idle levels and timing — use manufacturer tool for protocol check

Diagnostic algorithm

  1. Read and save all DTCs from all modules; note time stamps and freeze data. 2) Confirm whether the TCM responds to the scan tool and whether other modules report communication faults. 3) Verify battery voltage and charging system; recharge or replace if low. 4) Check/replace relevant fuses and relays for TCM and vehicle data bus. 5) Visually inspect and clean TCM connector and ground points; repair damaged pins/wires. 6) Measure power and ground at the TCM connector; repair any supply faults. 7) Measure termination resistance and use a scope or CAN‑bus tool to observe message traffic and verify proper recessive/dominant levels. 8) Isolate sections of the network (disconnect non‑essential nodes) to find the failing node if bus is shorted. 9) If wiring and bus signals are correct but communication still fails, verify software/coding and reflash modules per manufacturer procedure. 10) Replace TCM only after confirming wiring, power/ground, and bus integrity; program/recode new module and recheck. 11) Clear codes and perform road test; re-scan to confirm repair.
  2. similar_codes([

Likely causes

  • Damaged/loose connector or wiring to the TCM
  • Power or ground fault at the TCM (fuse, relay, battery)
  • CAN bus fault (short to battery/ground or open, missing termination)
  • Faulty TCM hardware or corrupted firmware
  • ECM/other network module not forwarding messages

Fault status

⚠️ Status
TCM not communicating on serial link (communication lost/invalid). Check wiring, power/grounds, CAN/serial bus, and module connectivity.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 1.5-3.0 hours

Similar codes

U0100 U0101 U0073 U0121 P0700
413

Browse 413 LAND ROVER manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.

LAND ROVER

Your experience will help others
+100 karma for a short comment :)
Keep it short and practical. Up to 500 characters.
Send to email
Code

P1611

MERCEDES-BENZ P — Powertrain

IFI Control Module N37

Brand: MERCEDES-BENZ
Type: P — Powertrain
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Open or shorted CAN/serial communication wires
  • Corroded/damaged connectors at the TCM or junctions
  • Blown fuse or faulty relay supplying TCM power
  • Weak battery or poor chassis ground causing module reset
  • Faulty or unresponsive Transmission Control Module (TCM)
  • Faulty engine/vehicle control module (ECM/BCM) that bridges the bus

Symptoms

  • Check Engine / Transmission warning lamp illuminated
  • Transmission enters limp/torque‑limited mode or won’t shift properly
  • No TCM present or no response when scanned with diagnostic tool
  • Erratic gear selection or fixed gear/lockup behavior
  • Intermittent loss of communication messages on scanner live data
  • Related instrument cluster or speedometer faults if bus messages missing

What to check

  • Obtain and record all stored and pending codes from all modules (scan tool)
  • Confirm whether TCM is present on the diagnostic network (module list)
  • Check battery voltage and charge state, test while cranking and with ignition on (should be stable)
  • Inspect fuses/relays for TCM power and main vehicle bus fuses
  • Visually inspect TCM connectors and wiring for corrosion, bent pins or damage
  • Measure power and ground at the TCM connector with ignition ON

Signal parameters

  • Typical CAN bus idle voltages: CAN‑H and CAN‑L ≈2.5 V each (recessive); dominant state creates ~2 V differential (CAN‑H higher, CAN‑L lower) — verify with scope
  • Expected termination: ~60 Ω measured between CAN‑H and CAN‑L (two 120 Ω resistors in parallel)
  • If vehicle uses single‑wire serial (K‑line) consult BMW repair manual for expected idle levels and timing — use manufacturer tool for protocol check

Diagnostic algorithm

  1. Read and save all DTCs from all modules; note time stamps and freeze data. 2) Confirm whether the TCM responds to the scan tool and whether other modules report communication faults. 3) Verify battery voltage and charging system; recharge or replace if low. 4) Check/replace relevant fuses and relays for TCM and vehicle data bus. 5) Visually inspect and clean TCM connector and ground points; repair damaged pins/wires. 6) Measure power and ground at the TCM connector; repair any supply faults. 7) Measure termination resistance and use a scope or CAN‑bus tool to observe message traffic and verify proper recessive/dominant levels. 8) Isolate sections of the network (disconnect non‑essential nodes) to find the failing node if bus is shorted. 9) If wiring and bus signals are correct but communication still fails, verify software/coding and reflash modules per manufacturer procedure. 10) Replace TCM only after confirming wiring, power/ground, and bus integrity; program/recode new module and recheck. 11) Clear codes and perform road test; re-scan to confirm repair.
  2. similar_codes([

Likely causes

  • Damaged/loose connector or wiring to the TCM
  • Power or ground fault at the TCM (fuse, relay, battery)
  • CAN bus fault (short to battery/ground or open, missing termination)
  • Faulty TCM hardware or corrupted firmware
  • ECM/other network module not forwarding messages

Fault status

⚠️ Status
TCM not communicating on serial link (communication lost/invalid). Check wiring, power/grounds, CAN/serial bus, and module connectivity.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 1.5-3.0 hours

Similar codes

U0100 U0101 U0073 U0121 P0700
856

Browse 856 MERCEDES-BENZ manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.

MERCEDES-BENZ

Your experience will help others
+100 karma for a short comment :)
Keep it short and practical. Up to 500 characters.
Send to email
Code

P1611

OLDSMOBILE P — Powertrain

Loss Of CVRTD Serial Data

Brand: OLDSMOBILE
Type: P — Powertrain
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Open or shorted CAN/serial communication wires
  • Corroded/damaged connectors at the TCM or junctions
  • Blown fuse or faulty relay supplying TCM power
  • Weak battery or poor chassis ground causing module reset
  • Faulty or unresponsive Transmission Control Module (TCM)
  • Faulty engine/vehicle control module (ECM/BCM) that bridges the bus

Symptoms

  • Check Engine / Transmission warning lamp illuminated
  • Transmission enters limp/torque‑limited mode or won’t shift properly
  • No TCM present or no response when scanned with diagnostic tool
  • Erratic gear selection or fixed gear/lockup behavior
  • Intermittent loss of communication messages on scanner live data
  • Related instrument cluster or speedometer faults if bus messages missing

What to check

  • Obtain and record all stored and pending codes from all modules (scan tool)
  • Confirm whether TCM is present on the diagnostic network (module list)
  • Check battery voltage and charge state, test while cranking and with ignition on (should be stable)
  • Inspect fuses/relays for TCM power and main vehicle bus fuses
  • Visually inspect TCM connectors and wiring for corrosion, bent pins or damage
  • Measure power and ground at the TCM connector with ignition ON

Signal parameters

  • Typical CAN bus idle voltages: CAN‑H and CAN‑L ≈2.5 V each (recessive); dominant state creates ~2 V differential (CAN‑H higher, CAN‑L lower) — verify with scope
  • Expected termination: ~60 Ω measured between CAN‑H and CAN‑L (two 120 Ω resistors in parallel)
  • If vehicle uses single‑wire serial (K‑line) consult BMW repair manual for expected idle levels and timing — use manufacturer tool for protocol check

Diagnostic algorithm

  1. Read and save all DTCs from all modules; note time stamps and freeze data. 2) Confirm whether the TCM responds to the scan tool and whether other modules report communication faults. 3) Verify battery voltage and charging system; recharge or replace if low. 4) Check/replace relevant fuses and relays for TCM and vehicle data bus. 5) Visually inspect and clean TCM connector and ground points; repair damaged pins/wires. 6) Measure power and ground at the TCM connector; repair any supply faults. 7) Measure termination resistance and use a scope or CAN‑bus tool to observe message traffic and verify proper recessive/dominant levels. 8) Isolate sections of the network (disconnect non‑essential nodes) to find the failing node if bus is shorted. 9) If wiring and bus signals are correct but communication still fails, verify software/coding and reflash modules per manufacturer procedure. 10) Replace TCM only after confirming wiring, power/ground, and bus integrity; program/recode new module and recheck. 11) Clear codes and perform road test; re-scan to confirm repair.
  2. similar_codes([

Likely causes

  • Damaged/loose connector or wiring to the TCM
  • Power or ground fault at the TCM (fuse, relay, battery)
  • CAN bus fault (short to battery/ground or open, missing termination)
  • Faulty TCM hardware or corrupted firmware
  • ECM/other network module not forwarding messages

Fault status

⚠️ Status
TCM not communicating on serial link (communication lost/invalid). Check wiring, power/grounds, CAN/serial bus, and module connectivity.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 1.5-3.0 hours

Similar codes

U0100 U0101 U0073 U0121 P0700
Your experience will help others
+100 karma for a short comment :)
Keep it short and practical. Up to 500 characters.
Send to email
Code

P1611

Other P — Powertrain

SBDS Interactive Codes

Brand: Other
Type: P — Powertrain
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Open or shorted CAN/serial communication wires
  • Corroded/damaged connectors at the TCM or junctions
  • Blown fuse or faulty relay supplying TCM power
  • Weak battery or poor chassis ground causing module reset
  • Faulty or unresponsive Transmission Control Module (TCM)
  • Faulty engine/vehicle control module (ECM/BCM) that bridges the bus

Symptoms

  • Check Engine / Transmission warning lamp illuminated
  • Transmission enters limp/torque‑limited mode or won’t shift properly
  • No TCM present or no response when scanned with diagnostic tool
  • Erratic gear selection or fixed gear/lockup behavior
  • Intermittent loss of communication messages on scanner live data
  • Related instrument cluster or speedometer faults if bus messages missing

What to check

  • Obtain and record all stored and pending codes from all modules (scan tool)
  • Confirm whether TCM is present on the diagnostic network (module list)
  • Check battery voltage and charge state, test while cranking and with ignition on (should be stable)
  • Inspect fuses/relays for TCM power and main vehicle bus fuses
  • Visually inspect TCM connectors and wiring for corrosion, bent pins or damage
  • Measure power and ground at the TCM connector with ignition ON

Signal parameters

  • Typical CAN bus idle voltages: CAN‑H and CAN‑L ≈2.5 V each (recessive); dominant state creates ~2 V differential (CAN‑H higher, CAN‑L lower) — verify with scope
  • Expected termination: ~60 Ω measured between CAN‑H and CAN‑L (two 120 Ω resistors in parallel)
  • If vehicle uses single‑wire serial (K‑line) consult BMW repair manual for expected idle levels and timing — use manufacturer tool for protocol check

Diagnostic algorithm

  1. Read and save all DTCs from all modules; note time stamps and freeze data. 2) Confirm whether the TCM responds to the scan tool and whether other modules report communication faults. 3) Verify battery voltage and charging system; recharge or replace if low. 4) Check/replace relevant fuses and relays for TCM and vehicle data bus. 5) Visually inspect and clean TCM connector and ground points; repair damaged pins/wires. 6) Measure power and ground at the TCM connector; repair any supply faults. 7) Measure termination resistance and use a scope or CAN‑bus tool to observe message traffic and verify proper recessive/dominant levels. 8) Isolate sections of the network (disconnect non‑essential nodes) to find the failing node if bus is shorted. 9) If wiring and bus signals are correct but communication still fails, verify software/coding and reflash modules per manufacturer procedure. 10) Replace TCM only after confirming wiring, power/ground, and bus integrity; program/recode new module and recheck. 11) Clear codes and perform road test; re-scan to confirm repair.
  2. similar_codes([

Likely causes

  • Damaged/loose connector or wiring to the TCM
  • Power or ground fault at the TCM (fuse, relay, battery)
  • CAN bus fault (short to battery/ground or open, missing termination)
  • Faulty TCM hardware or corrupted firmware
  • ECM/other network module not forwarding messages

Fault status

⚠️ Status
TCM not communicating on serial link (communication lost/invalid). Check wiring, power/grounds, CAN/serial bus, and module connectivity.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 1.5-3.0 hours

Similar codes

U0100 U0101 U0073 U0121 P0700
10,724

The library contains 10,724 repair and diagnostic manuals. Choose a brand to open the full manual tree by year, model and trim.

ALFA ROMEO
89
AUDI
1,243
BMW
479
CADILLAC
206
CHEVROLET
917
CHRYSLER
193
DAEWOO
75
FIAT
26
GENESIS
207
HUMMER
138
HYUNDAI
371
ISUZU
229
JEEP
575
KIA
155
LAND ROVER
413
LEXUS
280
LINCOLN
166
MERCEDES-BENZ
856
MERCURY
296
MITSUBISHI
406
PORSCHE
136
TESLA
81
TOYOTA
2,209
TRIUMPH
131
VOLKSWAGEN
626
VOLVO
221
Your experience will help others
+100 karma for a short comment :)
Keep it short and practical. Up to 500 characters.
Send to email
Code

P1611

PORSCHE P — Powertrain

MIL activated externally

Brand: PORSCHE
Type: P — Powertrain
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Open or shorted CAN/serial communication wires
  • Corroded/damaged connectors at the TCM or junctions
  • Blown fuse or faulty relay supplying TCM power
  • Weak battery or poor chassis ground causing module reset
  • Faulty or unresponsive Transmission Control Module (TCM)
  • Faulty engine/vehicle control module (ECM/BCM) that bridges the bus

Symptoms

  • Check Engine / Transmission warning lamp illuminated
  • Transmission enters limp/torque‑limited mode or won’t shift properly
  • No TCM present or no response when scanned with diagnostic tool
  • Erratic gear selection or fixed gear/lockup behavior
  • Intermittent loss of communication messages on scanner live data
  • Related instrument cluster or speedometer faults if bus messages missing

What to check

  • Obtain and record all stored and pending codes from all modules (scan tool)
  • Confirm whether TCM is present on the diagnostic network (module list)
  • Check battery voltage and charge state, test while cranking and with ignition on (should be stable)
  • Inspect fuses/relays for TCM power and main vehicle bus fuses
  • Visually inspect TCM connectors and wiring for corrosion, bent pins or damage
  • Measure power and ground at the TCM connector with ignition ON

Signal parameters

  • Typical CAN bus idle voltages: CAN‑H and CAN‑L ≈2.5 V each (recessive); dominant state creates ~2 V differential (CAN‑H higher, CAN‑L lower) — verify with scope
  • Expected termination: ~60 Ω measured between CAN‑H and CAN‑L (two 120 Ω resistors in parallel)
  • If vehicle uses single‑wire serial (K‑line) consult BMW repair manual for expected idle levels and timing — use manufacturer tool for protocol check

Diagnostic algorithm

  1. Read and save all DTCs from all modules; note time stamps and freeze data. 2) Confirm whether the TCM responds to the scan tool and whether other modules report communication faults. 3) Verify battery voltage and charging system; recharge or replace if low. 4) Check/replace relevant fuses and relays for TCM and vehicle data bus. 5) Visually inspect and clean TCM connector and ground points; repair damaged pins/wires. 6) Measure power and ground at the TCM connector; repair any supply faults. 7) Measure termination resistance and use a scope or CAN‑bus tool to observe message traffic and verify proper recessive/dominant levels. 8) Isolate sections of the network (disconnect non‑essential nodes) to find the failing node if bus is shorted. 9) If wiring and bus signals are correct but communication still fails, verify software/coding and reflash modules per manufacturer procedure. 10) Replace TCM only after confirming wiring, power/ground, and bus integrity; program/recode new module and recheck. 11) Clear codes and perform road test; re-scan to confirm repair.
  2. similar_codes([

Likely causes

  • Damaged/loose connector or wiring to the TCM
  • Power or ground fault at the TCM (fuse, relay, battery)
  • CAN bus fault (short to battery/ground or open, missing termination)
  • Faulty TCM hardware or corrupted firmware
  • ECM/other network module not forwarding messages

Fault status

⚠️ Status
TCM not communicating on serial link (communication lost/invalid). Check wiring, power/grounds, CAN/serial bus, and module connectivity.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 1.5-3.0 hours

Similar codes

U0100 U0101 U0073 U0121 P0700
136

Browse 136 PORSCHE manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.

PORSCHE

Your experience will help others
+100 karma for a short comment :)
Keep it short and practical. Up to 500 characters.
Send to email
Code

P1611

SAAB P — Powertrain

Check Engine Request, Short To Ground / Internal Module Malfunction

Brand: SAAB
Type: P — Powertrain
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Open or shorted CAN/serial communication wires
  • Corroded/damaged connectors at the TCM or junctions
  • Blown fuse or faulty relay supplying TCM power
  • Weak battery or poor chassis ground causing module reset
  • Faulty or unresponsive Transmission Control Module (TCM)
  • Faulty engine/vehicle control module (ECM/BCM) that bridges the bus

Symptoms

  • Check Engine / Transmission warning lamp illuminated
  • Transmission enters limp/torque‑limited mode or won’t shift properly
  • No TCM present or no response when scanned with diagnostic tool
  • Erratic gear selection or fixed gear/lockup behavior
  • Intermittent loss of communication messages on scanner live data
  • Related instrument cluster or speedometer faults if bus messages missing

What to check

  • Obtain and record all stored and pending codes from all modules (scan tool)
  • Confirm whether TCM is present on the diagnostic network (module list)
  • Check battery voltage and charge state, test while cranking and with ignition on (should be stable)
  • Inspect fuses/relays for TCM power and main vehicle bus fuses
  • Visually inspect TCM connectors and wiring for corrosion, bent pins or damage
  • Measure power and ground at the TCM connector with ignition ON

Signal parameters

  • Typical CAN bus idle voltages: CAN‑H and CAN‑L ≈2.5 V each (recessive); dominant state creates ~2 V differential (CAN‑H higher, CAN‑L lower) — verify with scope
  • Expected termination: ~60 Ω measured between CAN‑H and CAN‑L (two 120 Ω resistors in parallel)
  • If vehicle uses single‑wire serial (K‑line) consult BMW repair manual for expected idle levels and timing — use manufacturer tool for protocol check

Diagnostic algorithm

  1. Read and save all DTCs from all modules; note time stamps and freeze data. 2) Confirm whether the TCM responds to the scan tool and whether other modules report communication faults. 3) Verify battery voltage and charging system; recharge or replace if low. 4) Check/replace relevant fuses and relays for TCM and vehicle data bus. 5) Visually inspect and clean TCM connector and ground points; repair damaged pins/wires. 6) Measure power and ground at the TCM connector; repair any supply faults. 7) Measure termination resistance and use a scope or CAN‑bus tool to observe message traffic and verify proper recessive/dominant levels. 8) Isolate sections of the network (disconnect non‑essential nodes) to find the failing node if bus is shorted. 9) If wiring and bus signals are correct but communication still fails, verify software/coding and reflash modules per manufacturer procedure. 10) Replace TCM only after confirming wiring, power/ground, and bus integrity; program/recode new module and recheck. 11) Clear codes and perform road test; re-scan to confirm repair.
  2. similar_codes([

Likely causes

  • Damaged/loose connector or wiring to the TCM
  • Power or ground fault at the TCM (fuse, relay, battery)
  • CAN bus fault (short to battery/ground or open, missing termination)
  • Faulty TCM hardware or corrupted firmware
  • ECM/other network module not forwarding messages

Fault status

⚠️ Status
TCM not communicating on serial link (communication lost/invalid). Check wiring, power/grounds, CAN/serial bus, and module connectivity.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 1.5-3.0 hours

Similar codes

U0100 U0101 U0073 U0121 P0700
Your experience will help others
+100 karma for a short comment :)
Keep it short and practical. Up to 500 characters.
Send to email
Code

P1611

SATURN P — Powertrain

Loss Of CVRTD Serial Data

Brand: SATURN
Type: P — Powertrain
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Open or shorted CAN/serial communication wires
  • Corroded/damaged connectors at the TCM or junctions
  • Blown fuse or faulty relay supplying TCM power
  • Weak battery or poor chassis ground causing module reset
  • Faulty or unresponsive Transmission Control Module (TCM)
  • Faulty engine/vehicle control module (ECM/BCM) that bridges the bus

Symptoms

  • Check Engine / Transmission warning lamp illuminated
  • Transmission enters limp/torque‑limited mode or won’t shift properly
  • No TCM present or no response when scanned with diagnostic tool
  • Erratic gear selection or fixed gear/lockup behavior
  • Intermittent loss of communication messages on scanner live data
  • Related instrument cluster or speedometer faults if bus messages missing

What to check

  • Obtain and record all stored and pending codes from all modules (scan tool)
  • Confirm whether TCM is present on the diagnostic network (module list)
  • Check battery voltage and charge state, test while cranking and with ignition on (should be stable)
  • Inspect fuses/relays for TCM power and main vehicle bus fuses
  • Visually inspect TCM connectors and wiring for corrosion, bent pins or damage
  • Measure power and ground at the TCM connector with ignition ON

Signal parameters

  • Typical CAN bus idle voltages: CAN‑H and CAN‑L ≈2.5 V each (recessive); dominant state creates ~2 V differential (CAN‑H higher, CAN‑L lower) — verify with scope
  • Expected termination: ~60 Ω measured between CAN‑H and CAN‑L (two 120 Ω resistors in parallel)
  • If vehicle uses single‑wire serial (K‑line) consult BMW repair manual for expected idle levels and timing — use manufacturer tool for protocol check

Diagnostic algorithm

  1. Read and save all DTCs from all modules; note time stamps and freeze data. 2) Confirm whether the TCM responds to the scan tool and whether other modules report communication faults. 3) Verify battery voltage and charging system; recharge or replace if low. 4) Check/replace relevant fuses and relays for TCM and vehicle data bus. 5) Visually inspect and clean TCM connector and ground points; repair damaged pins/wires. 6) Measure power and ground at the TCM connector; repair any supply faults. 7) Measure termination resistance and use a scope or CAN‑bus tool to observe message traffic and verify proper recessive/dominant levels. 8) Isolate sections of the network (disconnect non‑essential nodes) to find the failing node if bus is shorted. 9) If wiring and bus signals are correct but communication still fails, verify software/coding and reflash modules per manufacturer procedure. 10) Replace TCM only after confirming wiring, power/ground, and bus integrity; program/recode new module and recheck. 11) Clear codes and perform road test; re-scan to confirm repair.
  2. similar_codes([

Likely causes

  • Damaged/loose connector or wiring to the TCM
  • Power or ground fault at the TCM (fuse, relay, battery)
  • CAN bus fault (short to battery/ground or open, missing termination)
  • Faulty TCM hardware or corrupted firmware
  • ECM/other network module not forwarding messages

Fault status

⚠️ Status
TCM not communicating on serial link (communication lost/invalid). Check wiring, power/grounds, CAN/serial bus, and module connectivity.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 1.5-3.0 hours

Similar codes

U0100 U0101 U0073 U0121 P0700
Your experience will help others
+100 karma for a short comment :)
Keep it short and practical. Up to 500 characters.
Send to email
Code

P1611

VOLKSWAGEN P — Powertrain

MIL Call-Up Circuit TCM Short To Ground

Brand: VOLKSWAGEN
Type: P — Powertrain
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Open or shorted CAN/serial communication wires
  • Corroded/damaged connectors at the TCM or junctions
  • Blown fuse or faulty relay supplying TCM power
  • Weak battery or poor chassis ground causing module reset
  • Faulty or unresponsive Transmission Control Module (TCM)
  • Faulty engine/vehicle control module (ECM/BCM) that bridges the bus

Symptoms

  • Check Engine / Transmission warning lamp illuminated
  • Transmission enters limp/torque‑limited mode or won’t shift properly
  • No TCM present or no response when scanned with diagnostic tool
  • Erratic gear selection or fixed gear/lockup behavior
  • Intermittent loss of communication messages on scanner live data
  • Related instrument cluster or speedometer faults if bus messages missing

What to check

  • Obtain and record all stored and pending codes from all modules (scan tool)
  • Confirm whether TCM is present on the diagnostic network (module list)
  • Check battery voltage and charge state, test while cranking and with ignition on (should be stable)
  • Inspect fuses/relays for TCM power and main vehicle bus fuses
  • Visually inspect TCM connectors and wiring for corrosion, bent pins or damage
  • Measure power and ground at the TCM connector with ignition ON

Signal parameters

  • Typical CAN bus idle voltages: CAN‑H and CAN‑L ≈2.5 V each (recessive); dominant state creates ~2 V differential (CAN‑H higher, CAN‑L lower) — verify with scope
  • Expected termination: ~60 Ω measured between CAN‑H and CAN‑L (two 120 Ω resistors in parallel)
  • If vehicle uses single‑wire serial (K‑line) consult BMW repair manual for expected idle levels and timing — use manufacturer tool for protocol check

Diagnostic algorithm

  1. Read and save all DTCs from all modules; note time stamps and freeze data. 2) Confirm whether the TCM responds to the scan tool and whether other modules report communication faults. 3) Verify battery voltage and charging system; recharge or replace if low. 4) Check/replace relevant fuses and relays for TCM and vehicle data bus. 5) Visually inspect and clean TCM connector and ground points; repair damaged pins/wires. 6) Measure power and ground at the TCM connector; repair any supply faults. 7) Measure termination resistance and use a scope or CAN‑bus tool to observe message traffic and verify proper recessive/dominant levels. 8) Isolate sections of the network (disconnect non‑essential nodes) to find the failing node if bus is shorted. 9) If wiring and bus signals are correct but communication still fails, verify software/coding and reflash modules per manufacturer procedure. 10) Replace TCM only after confirming wiring, power/ground, and bus integrity; program/recode new module and recheck. 11) Clear codes and perform road test; re-scan to confirm repair.
  2. similar_codes([

Likely causes

  • Damaged/loose connector or wiring to the TCM
  • Power or ground fault at the TCM (fuse, relay, battery)
  • CAN bus fault (short to battery/ground or open, missing termination)
  • Faulty TCM hardware or corrupted firmware
  • ECM/other network module not forwarding messages

Fault status

⚠️ Status
TCM not communicating on serial link (communication lost/invalid). Check wiring, power/grounds, CAN/serial bus, and module connectivity.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 1.5-3.0 hours

Similar codes

U0100 U0101 U0073 U0121 P0700
626

Browse 626 VOLKSWAGEN manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.

VOLKSWAGEN

Your experience will help others
+100 karma for a short comment :)
Keep it short and practical. Up to 500 characters.
Send to email

Report

Harassment or bullying behavior
Contains mature or sensitive content
Contains misleading or false information
Contains abusive or derogatory content
Contains spam, fake content or potential malware

Block Member?

Please confirm you want to block this member.

You will no longer be able to:

  • See blocked member's posts
  • Mention this member in posts
  • Invite this member to groups
  • Message this member
  • Add this member as a connection

Please note: This action will also remove this member from your connections and send a report to the site admin. Please allow a few minutes for this process to complete.

Report

You have already reported this .