Code
P0740
Generic
P — Powertrain
Torque Converter Clutch Circuit/Open
Views:
UK: 32
EN: 38
RU: 66
AI status
Completed
Completed
100%
Causes
- Open or shorted wiring in TCC circuit
- Failed TCC solenoid (coil open/short)
- Poor or corroded connector or pin
- Blown fuse or faulty relay in transmission control power/ground
- Low or contaminated automatic transmission fluid (ATF) causing stuck valve
- Internal transmission hydraulic fault (sticking valve, damaged torque converter)
Symptoms
- Check Engine Light / MIL illuminated (P0740 set)
- Torque converter fails to lock up — higher RPMs at cruise
- Poor fuel economy, increased engine RPMs at steady speed
- Transmission slipping or harsh/erratic shifts
- Transmission or engine overheat (increased operating temp)
- Delayed or rough engagement into drive or gears
What to check
- Verify stored freeze frame and pending codes with scan tool; re-check after clearing and drive-cycle
- Monitor live data: TCC commanded state, TCC actual/pressure (if available), transmission range and speed
- Visually inspect wiring harness and connectors at transmission for damage, corrosion, or loose pins
- Check transmission fluid level and condition (color, smell, debris)
- Check fuses and relays related to transmission/TCM power and grounds
- Backprobe TCC solenoid connector: measure reference voltage, switched ground, and PWM duty when commanded
Signal parameters
- TCC control is typically a switched ground or PWM-controlled solenoid from the TCM
- Typical solenoid coil resistance range (varies by vehicle): roughly 10–40 ohms (measure and compare to spec)
- Reference supply: ~12 V (key ON) to the circuit supply pin; control often provides ground/PWM from TCM
- PWM control can vary: 0–100% duty cycle; frequency often tens to a few hundred Hz depending on manufacturer
- Expected behavior: command ON should produce a measurable change in duty/voltage and corresponding TCC engagement/pressure (verify with live data)
Diagnostic algorithm
- Connect a capable scan tool; record freeze frame and live data for TCC command and related PIDs. Note conditions when code set.
- Clear code, perform a controlled test drive to reproduce. Confirm code returns and note conditions.
- Visually inspect connectors and wiring between TCM/ECM and transmission; repair any chafing, corrosion, or loose pins.
- With ignition ON (engine off), backprobe the TCC solenoid connector. Verify reference supply (~12V) and that control lead is low/high as expected when commanded by scan tool.
- Measure solenoid coil resistance with a multimeter. Compare to manufacturer spec; an open circuit indicates failed solenoid.
- Using the scan tool, command the TCC ON/OFF and observe voltage/duty at the connector. Look for proper PWM or switching and corresponding change in engine RPM/lock-up indication.
- If wiring and connector are good but control signal is not present, check fuses/relays and ground circuits. Trace continuity to the TCM and check for shorts to power or ground.
- If electrical circuit is good and solenoid operates but code persists, check ATF level/condition and perform transmission hydraulic pressure and stall tests to confirm valve body and torque converter functionality.
- If wiring, solenoid, and hydraulics are verified, suspect TCM/ECM driver fault; consult manufacturer guidance before replacing control module.
- After repairs, clear codes and perform a full road test and re-check for stored codes. Document findings and repairs.
Likely causes
- Broken/shorted harness to TCC solenoid
- Faulty TCC solenoid coil (open circuit)
- Corroded connector or poor ground at transmission
- Low ATF or severely degraded fluid causing internal sticking
Fault status
Status
P0740 — Torque Converter Clutch Circuit/Open: control module detected open or out-of-range signal in the TCC circuit. MIL illuminated; lock-up control disabled until condition resolved.
Repair difficulty: Medium
Diagnostic time: 1.0-3.0 hours (varies by vehicle and accessibility)
Similar codes
Your experience will help others
+100 karma for a short comment :)
Was this AI description helpful?
Your feedback helps improve AI descriptions.
👍 Like
0
👎 Dislike
0
Send to email
Code
P0740
GWM
P — Powertrain
- Malfunction in the clutch chain
Views:
UK: 15
EN: 20
RU: 22
AI status
Completed
Completed
100%
Causes
- Open or shorted wiring in TCC circuit
- Failed TCC solenoid (coil open/short)
- Poor or corroded connector or pin
- Blown fuse or faulty relay in transmission control power/ground
- Low or contaminated automatic transmission fluid (ATF) causing stuck valve
- Internal transmission hydraulic fault (sticking valve, damaged torque converter)
Symptoms
- Check Engine Light / MIL illuminated (P0740 set)
- Torque converter fails to lock up — higher RPMs at cruise
- Poor fuel economy, increased engine RPMs at steady speed
- Transmission slipping or harsh/erratic shifts
- Transmission or engine overheat (increased operating temp)
- Delayed or rough engagement into drive or gears
What to check
- Verify stored freeze frame and pending codes with scan tool; re-check after clearing and drive-cycle
- Monitor live data: TCC commanded state, TCC actual/pressure (if available), transmission range and speed
- Visually inspect wiring harness and connectors at transmission for damage, corrosion, or loose pins
- Check transmission fluid level and condition (color, smell, debris)
- Check fuses and relays related to transmission/TCM power and grounds
- Backprobe TCC solenoid connector: measure reference voltage, switched ground, and PWM duty when commanded
Signal parameters
- TCC control is typically a switched ground or PWM-controlled solenoid from the TCM
- Typical solenoid coil resistance range (varies by vehicle): roughly 10–40 ohms (measure and compare to spec)
- Reference supply: ~12 V (key ON) to the circuit supply pin; control often provides ground/PWM from TCM
- PWM control can vary: 0–100% duty cycle; frequency often tens to a few hundred Hz depending on manufacturer
- Expected behavior: command ON should produce a measurable change in duty/voltage and corresponding TCC engagement/pressure (verify with live data)
Diagnostic algorithm
- Connect a capable scan tool; record freeze frame and live data for TCC command and related PIDs. Note conditions when code set.
- Clear code, perform a controlled test drive to reproduce. Confirm code returns and note conditions.
- Visually inspect connectors and wiring between TCM/ECM and transmission; repair any chafing, corrosion, or loose pins.
- With ignition ON (engine off), backprobe the TCC solenoid connector. Verify reference supply (~12V) and that control lead is low/high as expected when commanded by scan tool.
- Measure solenoid coil resistance with a multimeter. Compare to manufacturer spec; an open circuit indicates failed solenoid.
- Using the scan tool, command the TCC ON/OFF and observe voltage/duty at the connector. Look for proper PWM or switching and corresponding change in engine RPM/lock-up indication.
- If wiring and connector are good but control signal is not present, check fuses/relays and ground circuits. Trace continuity to the TCM and check for shorts to power or ground.
- If electrical circuit is good and solenoid operates but code persists, check ATF level/condition and perform transmission hydraulic pressure and stall tests to confirm valve body and torque converter functionality.
- If wiring, solenoid, and hydraulics are verified, suspect TCM/ECM driver fault; consult manufacturer guidance before replacing control module.
- After repairs, clear codes and perform a full road test and re-check for stored codes. Document findings and repairs.
Likely causes
- Broken/shorted harness to TCC solenoid
- Faulty TCC solenoid coil (open circuit)
- Corroded connector or poor ground at transmission
- Low ATF or severely degraded fluid causing internal sticking
Fault status
Status
P0740 — Torque Converter Clutch Circuit/Open: control module detected open or out-of-range signal in the TCC circuit. MIL illuminated; lock-up control disabled until condition resolved.
Repair difficulty: Medium
Diagnostic time: 1.0-3.0 hours (varies by vehicle and accessibility)
Similar codes
Your experience will help others
+100 karma for a short comment :)
Was this AI description helpful?
Your feedback helps improve AI descriptions.
👍 Like
0
👎 Dislike
0
Send to email
Code
P0740
HUMMER
P — Powertrain
TCC Enable Solenoid Circuit Electrical
Views:
UK: 15
EN: 27
RU: 34
AI status
Completed
Completed
100%
Causes
- Open or shorted wiring in TCC circuit
- Failed TCC solenoid (coil open/short)
- Poor or corroded connector or pin
- Blown fuse or faulty relay in transmission control power/ground
- Low or contaminated automatic transmission fluid (ATF) causing stuck valve
- Internal transmission hydraulic fault (sticking valve, damaged torque converter)
Symptoms
- Check Engine Light / MIL illuminated (P0740 set)
- Torque converter fails to lock up — higher RPMs at cruise
- Poor fuel economy, increased engine RPMs at steady speed
- Transmission slipping or harsh/erratic shifts
- Transmission or engine overheat (increased operating temp)
- Delayed or rough engagement into drive or gears
What to check
- Verify stored freeze frame and pending codes with scan tool; re-check after clearing and drive-cycle
- Monitor live data: TCC commanded state, TCC actual/pressure (if available), transmission range and speed
- Visually inspect wiring harness and connectors at transmission for damage, corrosion, or loose pins
- Check transmission fluid level and condition (color, smell, debris)
- Check fuses and relays related to transmission/TCM power and grounds
- Backprobe TCC solenoid connector: measure reference voltage, switched ground, and PWM duty when commanded
Signal parameters
- TCC control is typically a switched ground or PWM-controlled solenoid from the TCM
- Typical solenoid coil resistance range (varies by vehicle): roughly 10–40 ohms (measure and compare to spec)
- Reference supply: ~12 V (key ON) to the circuit supply pin; control often provides ground/PWM from TCM
- PWM control can vary: 0–100% duty cycle; frequency often tens to a few hundred Hz depending on manufacturer
- Expected behavior: command ON should produce a measurable change in duty/voltage and corresponding TCC engagement/pressure (verify with live data)
Diagnostic algorithm
- Connect a capable scan tool; record freeze frame and live data for TCC command and related PIDs. Note conditions when code set.
- Clear code, perform a controlled test drive to reproduce. Confirm code returns and note conditions.
- Visually inspect connectors and wiring between TCM/ECM and transmission; repair any chafing, corrosion, or loose pins.
- With ignition ON (engine off), backprobe the TCC solenoid connector. Verify reference supply (~12V) and that control lead is low/high as expected when commanded by scan tool.
- Measure solenoid coil resistance with a multimeter. Compare to manufacturer spec; an open circuit indicates failed solenoid.
- Using the scan tool, command the TCC ON/OFF and observe voltage/duty at the connector. Look for proper PWM or switching and corresponding change in engine RPM/lock-up indication.
- If wiring and connector are good but control signal is not present, check fuses/relays and ground circuits. Trace continuity to the TCM and check for shorts to power or ground.
- If electrical circuit is good and solenoid operates but code persists, check ATF level/condition and perform transmission hydraulic pressure and stall tests to confirm valve body and torque converter functionality.
- If wiring, solenoid, and hydraulics are verified, suspect TCM/ECM driver fault; consult manufacturer guidance before replacing control module.
- After repairs, clear codes and perform a full road test and re-check for stored codes. Document findings and repairs.
Likely causes
- Broken/shorted harness to TCC solenoid
- Faulty TCC solenoid coil (open circuit)
- Corroded connector or poor ground at transmission
- Low ATF or severely degraded fluid causing internal sticking
Fault status
Status
P0740 — Torque Converter Clutch Circuit/Open: control module detected open or out-of-range signal in the TCC circuit. MIL illuminated; lock-up control disabled until condition resolved.
Repair difficulty: Medium
Diagnostic time: 1.0-3.0 hours (varies by vehicle and accessibility)
Similar codes
HTML Workshop Manuals AI manual library for HUMMER Click to show available manuals 77
HUMMER 2010 H3 Alpha
HTML ManualHUMMER 2010 H3 Base, Standard
HTML ManualHUMMER 2010 H3 Base, Automatic
HTML ManualHUMMER 2010 H3T Alpha
HTML ManualHUMMER 2010 H3T Base, Standard
HTML ManualHUMMER 2010 H3T Base, Automatic
HTML ManualHUMMER 2009 H2 4D Utility Wagon
HTML ManualHUMMER 2009 H2 4D Utility Pickup
HTML ManualYour experience will help others
+100 karma for a short comment :)
Was this AI description helpful?
Your feedback helps improve AI descriptions.
👍 Like
0
👎 Dislike
0
Send to email
Code
P0740
LAND ROVER
P — Powertrain
Failure in the torque converter clutch circuit
Views:
UK: 16
EN: 27
RU: 28
AI status
Completed
Completed
100%
Causes
- Open or shorted wiring in TCC circuit
- Failed TCC solenoid (coil open/short)
- Poor or corroded connector or pin
- Blown fuse or faulty relay in transmission control power/ground
- Low or contaminated automatic transmission fluid (ATF) causing stuck valve
- Internal transmission hydraulic fault (sticking valve, damaged torque converter)
Symptoms
- Check Engine Light / MIL illuminated (P0740 set)
- Torque converter fails to lock up — higher RPMs at cruise
- Poor fuel economy, increased engine RPMs at steady speed
- Transmission slipping or harsh/erratic shifts
- Transmission or engine overheat (increased operating temp)
- Delayed or rough engagement into drive or gears
What to check
- Verify stored freeze frame and pending codes with scan tool; re-check after clearing and drive-cycle
- Monitor live data: TCC commanded state, TCC actual/pressure (if available), transmission range and speed
- Visually inspect wiring harness and connectors at transmission for damage, corrosion, or loose pins
- Check transmission fluid level and condition (color, smell, debris)
- Check fuses and relays related to transmission/TCM power and grounds
- Backprobe TCC solenoid connector: measure reference voltage, switched ground, and PWM duty when commanded
Signal parameters
- TCC control is typically a switched ground or PWM-controlled solenoid from the TCM
- Typical solenoid coil resistance range (varies by vehicle): roughly 10–40 ohms (measure and compare to spec)
- Reference supply: ~12 V (key ON) to the circuit supply pin; control often provides ground/PWM from TCM
- PWM control can vary: 0–100% duty cycle; frequency often tens to a few hundred Hz depending on manufacturer
- Expected behavior: command ON should produce a measurable change in duty/voltage and corresponding TCC engagement/pressure (verify with live data)
Diagnostic algorithm
- Connect a capable scan tool; record freeze frame and live data for TCC command and related PIDs. Note conditions when code set.
- Clear code, perform a controlled test drive to reproduce. Confirm code returns and note conditions.
- Visually inspect connectors and wiring between TCM/ECM and transmission; repair any chafing, corrosion, or loose pins.
- With ignition ON (engine off), backprobe the TCC solenoid connector. Verify reference supply (~12V) and that control lead is low/high as expected when commanded by scan tool.
- Measure solenoid coil resistance with a multimeter. Compare to manufacturer spec; an open circuit indicates failed solenoid.
- Using the scan tool, command the TCC ON/OFF and observe voltage/duty at the connector. Look for proper PWM or switching and corresponding change in engine RPM/lock-up indication.
- If wiring and connector are good but control signal is not present, check fuses/relays and ground circuits. Trace continuity to the TCM and check for shorts to power or ground.
- If electrical circuit is good and solenoid operates but code persists, check ATF level/condition and perform transmission hydraulic pressure and stall tests to confirm valve body and torque converter functionality.
- If wiring, solenoid, and hydraulics are verified, suspect TCM/ECM driver fault; consult manufacturer guidance before replacing control module.
- After repairs, clear codes and perform a full road test and re-check for stored codes. Document findings and repairs.
Likely causes
- Broken/shorted harness to TCC solenoid
- Faulty TCC solenoid coil (open circuit)
- Corroded connector or poor ground at transmission
- Low ATF or severely degraded fluid causing internal sticking
Fault status
Status
P0740 — Torque Converter Clutch Circuit/Open: control module detected open or out-of-range signal in the TCC circuit. MIL illuminated; lock-up control disabled until condition resolved.
Repair difficulty: Medium
Diagnostic time: 1.0-3.0 hours (varies by vehicle and accessibility)
Similar codes
Your experience will help others
+100 karma for a short comment :)
Was this AI description helpful?
Your feedback helps improve AI descriptions.
👍 Like
0
👎 Dislike
0
Send to email
Code
P0740
MERCEDES-BENZ
P — Powertrain
Torque Converter Clutch Circuit Malfuction
Views:
UK: 21
EN: 36
RU: 35
AI status
Completed
Completed
100%
Causes
- Open or shorted wiring in TCC circuit
- Failed TCC solenoid (coil open/short)
- Poor or corroded connector or pin
- Blown fuse or faulty relay in transmission control power/ground
- Low or contaminated automatic transmission fluid (ATF) causing stuck valve
- Internal transmission hydraulic fault (sticking valve, damaged torque converter)
Symptoms
- Check Engine Light / MIL illuminated (P0740 set)
- Torque converter fails to lock up — higher RPMs at cruise
- Poor fuel economy, increased engine RPMs at steady speed
- Transmission slipping or harsh/erratic shifts
- Transmission or engine overheat (increased operating temp)
- Delayed or rough engagement into drive or gears
What to check
- Verify stored freeze frame and pending codes with scan tool; re-check after clearing and drive-cycle
- Monitor live data: TCC commanded state, TCC actual/pressure (if available), transmission range and speed
- Visually inspect wiring harness and connectors at transmission for damage, corrosion, or loose pins
- Check transmission fluid level and condition (color, smell, debris)
- Check fuses and relays related to transmission/TCM power and grounds
- Backprobe TCC solenoid connector: measure reference voltage, switched ground, and PWM duty when commanded
Signal parameters
- TCC control is typically a switched ground or PWM-controlled solenoid from the TCM
- Typical solenoid coil resistance range (varies by vehicle): roughly 10–40 ohms (measure and compare to spec)
- Reference supply: ~12 V (key ON) to the circuit supply pin; control often provides ground/PWM from TCM
- PWM control can vary: 0–100% duty cycle; frequency often tens to a few hundred Hz depending on manufacturer
- Expected behavior: command ON should produce a measurable change in duty/voltage and corresponding TCC engagement/pressure (verify with live data)
Diagnostic algorithm
- Connect a capable scan tool; record freeze frame and live data for TCC command and related PIDs. Note conditions when code set.
- Clear code, perform a controlled test drive to reproduce. Confirm code returns and note conditions.
- Visually inspect connectors and wiring between TCM/ECM and transmission; repair any chafing, corrosion, or loose pins.
- With ignition ON (engine off), backprobe the TCC solenoid connector. Verify reference supply (~12V) and that control lead is low/high as expected when commanded by scan tool.
- Measure solenoid coil resistance with a multimeter. Compare to manufacturer spec; an open circuit indicates failed solenoid.
- Using the scan tool, command the TCC ON/OFF and observe voltage/duty at the connector. Look for proper PWM or switching and corresponding change in engine RPM/lock-up indication.
- If wiring and connector are good but control signal is not present, check fuses/relays and ground circuits. Trace continuity to the TCM and check for shorts to power or ground.
- If electrical circuit is good and solenoid operates but code persists, check ATF level/condition and perform transmission hydraulic pressure and stall tests to confirm valve body and torque converter functionality.
- If wiring, solenoid, and hydraulics are verified, suspect TCM/ECM driver fault; consult manufacturer guidance before replacing control module.
- After repairs, clear codes and perform a full road test and re-check for stored codes. Document findings and repairs.
Likely causes
- Broken/shorted harness to TCC solenoid
- Faulty TCC solenoid coil (open circuit)
- Corroded connector or poor ground at transmission
- Low ATF or severely degraded fluid causing internal sticking
Fault status
Status
P0740 — Torque Converter Clutch Circuit/Open: control module detected open or out-of-range signal in the TCC circuit. MIL illuminated; lock-up control disabled until condition resolved.
Repair difficulty: Medium
Diagnostic time: 1.0-3.0 hours (varies by vehicle and accessibility)
Similar codes
HTML Workshop Manuals AI manual library for MERCEDES-BENZ Click to show available manuals 576
MERCEDES-BENZ 2024 C300 Base
HTML ManualMERCEDES-BENZ 2024 C300 4Matic
HTML ManualMERCEDES-BENZ 2024 C43 AMG
HTML ManualMERCEDES-BENZ 2024 C63 S AMG E Performance
HTML ManualMERCEDES-BENZ 2024 CLA250 Base
HTML ManualMERCEDES-BENZ 2024 CLA250 4Matic
HTML ManualMERCEDES-BENZ 2024 CLA35 AMG
HTML ManualMERCEDES-BENZ 2024 CLA45 S AMG
HTML ManualYour experience will help others
+100 karma for a short comment :)
Was this AI description helpful?
Your feedback helps improve AI descriptions.
👍 Like
0
👎 Dislike
0
Send to email
Code
P0740
MITSUBISHI
P — Powertrain
DCC solenoid
Views:
UK: 12
EN: 30
RU: 30
AI status
Completed
Completed
100%
Causes
- Open or shorted wiring in TCC circuit
- Failed TCC solenoid (coil open/short)
- Poor or corroded connector or pin
- Blown fuse or faulty relay in transmission control power/ground
- Low or contaminated automatic transmission fluid (ATF) causing stuck valve
- Internal transmission hydraulic fault (sticking valve, damaged torque converter)
Symptoms
- Check Engine Light / MIL illuminated (P0740 set)
- Torque converter fails to lock up — higher RPMs at cruise
- Poor fuel economy, increased engine RPMs at steady speed
- Transmission slipping or harsh/erratic shifts
- Transmission or engine overheat (increased operating temp)
- Delayed or rough engagement into drive or gears
What to check
- Verify stored freeze frame and pending codes with scan tool; re-check after clearing and drive-cycle
- Monitor live data: TCC commanded state, TCC actual/pressure (if available), transmission range and speed
- Visually inspect wiring harness and connectors at transmission for damage, corrosion, or loose pins
- Check transmission fluid level and condition (color, smell, debris)
- Check fuses and relays related to transmission/TCM power and grounds
- Backprobe TCC solenoid connector: measure reference voltage, switched ground, and PWM duty when commanded
Signal parameters
- TCC control is typically a switched ground or PWM-controlled solenoid from the TCM
- Typical solenoid coil resistance range (varies by vehicle): roughly 10–40 ohms (measure and compare to spec)
- Reference supply: ~12 V (key ON) to the circuit supply pin; control often provides ground/PWM from TCM
- PWM control can vary: 0–100% duty cycle; frequency often tens to a few hundred Hz depending on manufacturer
- Expected behavior: command ON should produce a measurable change in duty/voltage and corresponding TCC engagement/pressure (verify with live data)
Diagnostic algorithm
- Connect a capable scan tool; record freeze frame and live data for TCC command and related PIDs. Note conditions when code set.
- Clear code, perform a controlled test drive to reproduce. Confirm code returns and note conditions.
- Visually inspect connectors and wiring between TCM/ECM and transmission; repair any chafing, corrosion, or loose pins.
- With ignition ON (engine off), backprobe the TCC solenoid connector. Verify reference supply (~12V) and that control lead is low/high as expected when commanded by scan tool.
- Measure solenoid coil resistance with a multimeter. Compare to manufacturer spec; an open circuit indicates failed solenoid.
- Using the scan tool, command the TCC ON/OFF and observe voltage/duty at the connector. Look for proper PWM or switching and corresponding change in engine RPM/lock-up indication.
- If wiring and connector are good but control signal is not present, check fuses/relays and ground circuits. Trace continuity to the TCM and check for shorts to power or ground.
- If electrical circuit is good and solenoid operates but code persists, check ATF level/condition and perform transmission hydraulic pressure and stall tests to confirm valve body and torque converter functionality.
- If wiring, solenoid, and hydraulics are verified, suspect TCM/ECM driver fault; consult manufacturer guidance before replacing control module.
- After repairs, clear codes and perform a full road test and re-check for stored codes. Document findings and repairs.
Likely causes
- Broken/shorted harness to TCC solenoid
- Faulty TCC solenoid coil (open circuit)
- Corroded connector or poor ground at transmission
- Low ATF or severely degraded fluid causing internal sticking
Fault status
Status
P0740 — Torque Converter Clutch Circuit/Open: control module detected open or out-of-range signal in the TCC circuit. MIL illuminated; lock-up control disabled until condition resolved.
Repair difficulty: Medium
Diagnostic time: 1.0-3.0 hours (varies by vehicle and accessibility)
Similar codes
Your experience will help others
+100 karma for a short comment :)
Was this AI description helpful?
Your feedback helps improve AI descriptions.
👍 Like
0
👎 Dislike
0
Send to email