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Home / DTC / U1108 — No communication with the engine management ECU fault: No signal

U1108 — No communication with the engine management ECU fault: No signal

Detailed page for trouble code U1108.

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22,491specific
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Code

U1108

CITROEN U — Network/User

No communication with the engine management ECU fault: No signal

Brand: CITROEN
Type: U — Network/User
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Engine management ECU powered down or fault
  • Blown fuse or loss of ECU supply/ground
  • Damaged or disconnected ECU connector(s)
  • Open/short or high resistance in CAN/LIN wiring between ECU and network
  • CAN bus terminated incorrectly or missing termination resistance
  • Bus off condition or network overload from another module

Symptoms

  • MIL/lamp(s) illuminated (ECU communication fault)
  • No engine data on dash (RPM, coolant temp, engine load missing)
  • Crank or no-start or engine goes into limp mode
  • Loss of driver aids that require engine data (cruise, traction control)
  • Other modules report related U-codes or communication timeouts

What to check

  • Record freeze frame / module list with a diagnostic scanner to confirm which module logged U1108
  • Check battery voltage (key on and cranking) — low battery can prevent ECU wake-up
  • Inspect engine ECU power and ground fuses/relays for presence and correct operation
  • Visually inspect ECU connector for damage, corrosion, bent pins or water ingress
  • Using a meter, measure supply voltage at ECU power pins and verify good ground continuity
  • Scan other modules for additional U-codes that indicate a network-wide issue

Signal parameters

  • Expected: periodic engine ECU CAN frames containing engine speed, coolant temp, throttle position (periods typically 20–200 ms depending on message)
  • CAN bus idle voltages (approx.): CAN_H ~2.5–3.5 V, CAN_L ~1.5–2.5 V (midline ~2.5 V)
  • Differential voltage during activity: pulses ±1 V from midline, valid CAN waveform shapes
  • Termination resistance: approx. 60 ohms measured between CAN_H and CAN_L (two 120Ω resistors in parallel)
  • No valid engine ECU CAN IDs or message timeout reported by gateway/instrument cluster

Diagnostic algorithm

  1. Retrieve full diagnostic data: read all U-codes and list of modules; note when U1108 is stored and any related codes.
  2. Verify battery state and recharge if low; reconnect and stabilize supply (some modules require stable voltage to communicate).
  3. With key ON, confirm fuses/relays powering the engine ECU are present and measure supply voltage at the ECU connector pin(s).
  4. Check grounds for continuity and corrosion — measure between ECU ground and chassis battery negative. Repair as needed.
  5. Inspect ECU connector for physical damage or water intrusion; repair/replace connector or wiring as required.
  6. Measure CAN_H and CAN_L voltages at a point near the ECU and elsewhere on the network to identify open/short or wiring fault. Replace wiring or repair shorted sections.
  7. Measure termination resistance between CAN_H and CAN_L with battery disconnected; verify ~60Ω. Add/repair termination resistors if incorrect.
  8. Use an oscilloscope or CAN bus tool to confirm presence/absence of engine ECU CAN frames and to identify bus-off or dominant-state conditions. If ECU frames absent but other modules transmit, suspect ECU power/ECU internal fault.
  9. If immobiliser or gateway controls wake lines, verify wake/sleep signals and check immobiliser status; consult vehicle-specific wiring to confirm wake-up sequence.
  10. If wiring, power and grounds OK but no communication, consider reflashing or replacing the engine ECU per manufacturer guidance; consult TSBs or manufacturer service information before replacement.
  11. After repairs, clear codes and test-drive to confirm restoration of normal communications and that no new U-codes return.

Likely causes

  • Lost power to engine ECU (fuse, relay, wiring)
  • Broken/loose connector pins at engine ECU
  • CAN high/low wiring short to battery/ground or open circuit
  • Missing CAN termination (≈60 ohm) or single-ended bus voltage out of range
  • ECU in sleep/standby and not being woken by gateway or immobiliser

Fault status

⚠️ Status
No communication/signal received from engine management ECU on vehicle network. ECU messages expected by gateway/instrument cluster are missing or timed out.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 1.5-4.0 hours

Similar codes

U0100 U0073 U0140 U0121 U1110
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Code

U1108

DS U — Network/User

No communication with the engine management ECU fault: No signal

Brand: DS
Type: U — Network/User
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Engine management ECU powered down or fault
  • Blown fuse or loss of ECU supply/ground
  • Damaged or disconnected ECU connector(s)
  • Open/short or high resistance in CAN/LIN wiring between ECU and network
  • CAN bus terminated incorrectly or missing termination resistance
  • Bus off condition or network overload from another module

Symptoms

  • MIL/lamp(s) illuminated (ECU communication fault)
  • No engine data on dash (RPM, coolant temp, engine load missing)
  • Crank or no-start or engine goes into limp mode
  • Loss of driver aids that require engine data (cruise, traction control)
  • Other modules report related U-codes or communication timeouts

What to check

  • Record freeze frame / module list with a diagnostic scanner to confirm which module logged U1108
  • Check battery voltage (key on and cranking) — low battery can prevent ECU wake-up
  • Inspect engine ECU power and ground fuses/relays for presence and correct operation
  • Visually inspect ECU connector for damage, corrosion, bent pins or water ingress
  • Using a meter, measure supply voltage at ECU power pins and verify good ground continuity
  • Scan other modules for additional U-codes that indicate a network-wide issue

Signal parameters

  • Expected: periodic engine ECU CAN frames containing engine speed, coolant temp, throttle position (periods typically 20–200 ms depending on message)
  • CAN bus idle voltages (approx.): CAN_H ~2.5–3.5 V, CAN_L ~1.5–2.5 V (midline ~2.5 V)
  • Differential voltage during activity: pulses ±1 V from midline, valid CAN waveform shapes
  • Termination resistance: approx. 60 ohms measured between CAN_H and CAN_L (two 120Ω resistors in parallel)
  • No valid engine ECU CAN IDs or message timeout reported by gateway/instrument cluster

Diagnostic algorithm

  1. Retrieve full diagnostic data: read all U-codes and list of modules; note when U1108 is stored and any related codes.
  2. Verify battery state and recharge if low; reconnect and stabilize supply (some modules require stable voltage to communicate).
  3. With key ON, confirm fuses/relays powering the engine ECU are present and measure supply voltage at the ECU connector pin(s).
  4. Check grounds for continuity and corrosion — measure between ECU ground and chassis battery negative. Repair as needed.
  5. Inspect ECU connector for physical damage or water intrusion; repair/replace connector or wiring as required.
  6. Measure CAN_H and CAN_L voltages at a point near the ECU and elsewhere on the network to identify open/short or wiring fault. Replace wiring or repair shorted sections.
  7. Measure termination resistance between CAN_H and CAN_L with battery disconnected; verify ~60Ω. Add/repair termination resistors if incorrect.
  8. Use an oscilloscope or CAN bus tool to confirm presence/absence of engine ECU CAN frames and to identify bus-off or dominant-state conditions. If ECU frames absent but other modules transmit, suspect ECU power/ECU internal fault.
  9. If immobiliser or gateway controls wake lines, verify wake/sleep signals and check immobiliser status; consult vehicle-specific wiring to confirm wake-up sequence.
  10. If wiring, power and grounds OK but no communication, consider reflashing or replacing the engine ECU per manufacturer guidance; consult TSBs or manufacturer service information before replacement.
  11. After repairs, clear codes and test-drive to confirm restoration of normal communications and that no new U-codes return.

Likely causes

  • Lost power to engine ECU (fuse, relay, wiring)
  • Broken/loose connector pins at engine ECU
  • CAN high/low wiring short to battery/ground or open circuit
  • Missing CAN termination (≈60 ohm) or single-ended bus voltage out of range
  • ECU in sleep/standby and not being woken by gateway or immobiliser

Fault status

⚠️ Status
No communication/signal received from engine management ECU on vehicle network. ECU messages expected by gateway/instrument cluster are missing or timed out.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 1.5-4.0 hours

Similar codes

U0100 U0073 U0140 U0121 U1110
Your experience will help others
+100 karma for a short comment :)
Keep it short and practical. Up to 500 characters.
Send to email
Code

U1108

MITSUBISHI U — Network/User

Meter CAN timeout/Not equipped

Brand: MITSUBISHI
Type: U — Network/User
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Engine management ECU powered down or fault
  • Blown fuse or loss of ECU supply/ground
  • Damaged or disconnected ECU connector(s)
  • Open/short or high resistance in CAN/LIN wiring between ECU and network
  • CAN bus terminated incorrectly or missing termination resistance
  • Bus off condition or network overload from another module

Symptoms

  • MIL/lamp(s) illuminated (ECU communication fault)
  • No engine data on dash (RPM, coolant temp, engine load missing)
  • Crank or no-start or engine goes into limp mode
  • Loss of driver aids that require engine data (cruise, traction control)
  • Other modules report related U-codes or communication timeouts

What to check

  • Record freeze frame / module list with a diagnostic scanner to confirm which module logged U1108
  • Check battery voltage (key on and cranking) — low battery can prevent ECU wake-up
  • Inspect engine ECU power and ground fuses/relays for presence and correct operation
  • Visually inspect ECU connector for damage, corrosion, bent pins or water ingress
  • Using a meter, measure supply voltage at ECU power pins and verify good ground continuity
  • Scan other modules for additional U-codes that indicate a network-wide issue

Signal parameters

  • Expected: periodic engine ECU CAN frames containing engine speed, coolant temp, throttle position (periods typically 20–200 ms depending on message)
  • CAN bus idle voltages (approx.): CAN_H ~2.5–3.5 V, CAN_L ~1.5–2.5 V (midline ~2.5 V)
  • Differential voltage during activity: pulses ±1 V from midline, valid CAN waveform shapes
  • Termination resistance: approx. 60 ohms measured between CAN_H and CAN_L (two 120Ω resistors in parallel)
  • No valid engine ECU CAN IDs or message timeout reported by gateway/instrument cluster

Diagnostic algorithm

  1. Retrieve full diagnostic data: read all U-codes and list of modules; note when U1108 is stored and any related codes.
  2. Verify battery state and recharge if low; reconnect and stabilize supply (some modules require stable voltage to communicate).
  3. With key ON, confirm fuses/relays powering the engine ECU are present and measure supply voltage at the ECU connector pin(s).
  4. Check grounds for continuity and corrosion — measure between ECU ground and chassis battery negative. Repair as needed.
  5. Inspect ECU connector for physical damage or water intrusion; repair/replace connector or wiring as required.
  6. Measure CAN_H and CAN_L voltages at a point near the ECU and elsewhere on the network to identify open/short or wiring fault. Replace wiring or repair shorted sections.
  7. Measure termination resistance between CAN_H and CAN_L with battery disconnected; verify ~60Ω. Add/repair termination resistors if incorrect.
  8. Use an oscilloscope or CAN bus tool to confirm presence/absence of engine ECU CAN frames and to identify bus-off or dominant-state conditions. If ECU frames absent but other modules transmit, suspect ECU power/ECU internal fault.
  9. If immobiliser or gateway controls wake lines, verify wake/sleep signals and check immobiliser status; consult vehicle-specific wiring to confirm wake-up sequence.
  10. If wiring, power and grounds OK but no communication, consider reflashing or replacing the engine ECU per manufacturer guidance; consult TSBs or manufacturer service information before replacement.
  11. After repairs, clear codes and test-drive to confirm restoration of normal communications and that no new U-codes return.

Likely causes

  • Lost power to engine ECU (fuse, relay, wiring)
  • Broken/loose connector pins at engine ECU
  • CAN high/low wiring short to battery/ground or open circuit
  • Missing CAN termination (≈60 ohm) or single-ended bus voltage out of range
  • ECU in sleep/standby and not being woken by gateway or immobiliser

Fault status

⚠️ Status
No communication/signal received from engine management ECU on vehicle network. ECU messages expected by gateway/instrument cluster are missing or timed out.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 1.5-4.0 hours

Similar codes

U0100 U0073 U0140 U0121 U1110
406

Browse 406 MITSUBISHI manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.

MITSUBISHI

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

U1108

Other U — Network/User

SCP (J1850) Invalid or Missing Data for Electric Traction Drive (Inverter)

Brand: Other
Type: U — Network/User
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Engine management ECU powered down or fault
  • Blown fuse or loss of ECU supply/ground
  • Damaged or disconnected ECU connector(s)
  • Open/short or high resistance in CAN/LIN wiring between ECU and network
  • CAN bus terminated incorrectly or missing termination resistance
  • Bus off condition or network overload from another module

Symptoms

  • MIL/lamp(s) illuminated (ECU communication fault)
  • No engine data on dash (RPM, coolant temp, engine load missing)
  • Crank or no-start or engine goes into limp mode
  • Loss of driver aids that require engine data (cruise, traction control)
  • Other modules report related U-codes or communication timeouts

What to check

  • Record freeze frame / module list with a diagnostic scanner to confirm which module logged U1108
  • Check battery voltage (key on and cranking) — low battery can prevent ECU wake-up
  • Inspect engine ECU power and ground fuses/relays for presence and correct operation
  • Visually inspect ECU connector for damage, corrosion, bent pins or water ingress
  • Using a meter, measure supply voltage at ECU power pins and verify good ground continuity
  • Scan other modules for additional U-codes that indicate a network-wide issue

Signal parameters

  • Expected: periodic engine ECU CAN frames containing engine speed, coolant temp, throttle position (periods typically 20–200 ms depending on message)
  • CAN bus idle voltages (approx.): CAN_H ~2.5–3.5 V, CAN_L ~1.5–2.5 V (midline ~2.5 V)
  • Differential voltage during activity: pulses ±1 V from midline, valid CAN waveform shapes
  • Termination resistance: approx. 60 ohms measured between CAN_H and CAN_L (two 120Ω resistors in parallel)
  • No valid engine ECU CAN IDs or message timeout reported by gateway/instrument cluster

Diagnostic algorithm

  1. Retrieve full diagnostic data: read all U-codes and list of modules; note when U1108 is stored and any related codes.
  2. Verify battery state and recharge if low; reconnect and stabilize supply (some modules require stable voltage to communicate).
  3. With key ON, confirm fuses/relays powering the engine ECU are present and measure supply voltage at the ECU connector pin(s).
  4. Check grounds for continuity and corrosion — measure between ECU ground and chassis battery negative. Repair as needed.
  5. Inspect ECU connector for physical damage or water intrusion; repair/replace connector or wiring as required.
  6. Measure CAN_H and CAN_L voltages at a point near the ECU and elsewhere on the network to identify open/short or wiring fault. Replace wiring or repair shorted sections.
  7. Measure termination resistance between CAN_H and CAN_L with battery disconnected; verify ~60Ω. Add/repair termination resistors if incorrect.
  8. Use an oscilloscope or CAN bus tool to confirm presence/absence of engine ECU CAN frames and to identify bus-off or dominant-state conditions. If ECU frames absent but other modules transmit, suspect ECU power/ECU internal fault.
  9. If immobiliser or gateway controls wake lines, verify wake/sleep signals and check immobiliser status; consult vehicle-specific wiring to confirm wake-up sequence.
  10. If wiring, power and grounds OK but no communication, consider reflashing or replacing the engine ECU per manufacturer guidance; consult TSBs or manufacturer service information before replacement.
  11. After repairs, clear codes and test-drive to confirm restoration of normal communications and that no new U-codes return.

Likely causes

  • Lost power to engine ECU (fuse, relay, wiring)
  • Broken/loose connector pins at engine ECU
  • CAN high/low wiring short to battery/ground or open circuit
  • Missing CAN termination (≈60 ohm) or single-ended bus voltage out of range
  • ECU in sleep/standby and not being woken by gateway or immobiliser

Fault status

⚠️ Status
No communication/signal received from engine management ECU on vehicle network. ECU messages expected by gateway/instrument cluster are missing or timed out.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 1.5-4.0 hours

Similar codes

U0100 U0073 U0140 U0121 U1110
8,735

The library contains 8,735 repair and diagnostic manuals. Choose a brand to open the full manual tree by year, model and trim.

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

U1108

PEUGEOT U — Network/User

No communication with the engine management ECU fault: No signal

Brand: PEUGEOT
Type: U — Network/User
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Engine management ECU powered down or fault
  • Blown fuse or loss of ECU supply/ground
  • Damaged or disconnected ECU connector(s)
  • Open/short or high resistance in CAN/LIN wiring between ECU and network
  • CAN bus terminated incorrectly or missing termination resistance
  • Bus off condition or network overload from another module

Symptoms

  • MIL/lamp(s) illuminated (ECU communication fault)
  • No engine data on dash (RPM, coolant temp, engine load missing)
  • Crank or no-start or engine goes into limp mode
  • Loss of driver aids that require engine data (cruise, traction control)
  • Other modules report related U-codes or communication timeouts

What to check

  • Record freeze frame / module list with a diagnostic scanner to confirm which module logged U1108
  • Check battery voltage (key on and cranking) — low battery can prevent ECU wake-up
  • Inspect engine ECU power and ground fuses/relays for presence and correct operation
  • Visually inspect ECU connector for damage, corrosion, bent pins or water ingress
  • Using a meter, measure supply voltage at ECU power pins and verify good ground continuity
  • Scan other modules for additional U-codes that indicate a network-wide issue

Signal parameters

  • Expected: periodic engine ECU CAN frames containing engine speed, coolant temp, throttle position (periods typically 20–200 ms depending on message)
  • CAN bus idle voltages (approx.): CAN_H ~2.5–3.5 V, CAN_L ~1.5–2.5 V (midline ~2.5 V)
  • Differential voltage during activity: pulses ±1 V from midline, valid CAN waveform shapes
  • Termination resistance: approx. 60 ohms measured between CAN_H and CAN_L (two 120Ω resistors in parallel)
  • No valid engine ECU CAN IDs or message timeout reported by gateway/instrument cluster

Diagnostic algorithm

  1. Retrieve full diagnostic data: read all U-codes and list of modules; note when U1108 is stored and any related codes.
  2. Verify battery state and recharge if low; reconnect and stabilize supply (some modules require stable voltage to communicate).
  3. With key ON, confirm fuses/relays powering the engine ECU are present and measure supply voltage at the ECU connector pin(s).
  4. Check grounds for continuity and corrosion — measure between ECU ground and chassis battery negative. Repair as needed.
  5. Inspect ECU connector for physical damage or water intrusion; repair/replace connector or wiring as required.
  6. Measure CAN_H and CAN_L voltages at a point near the ECU and elsewhere on the network to identify open/short or wiring fault. Replace wiring or repair shorted sections.
  7. Measure termination resistance between CAN_H and CAN_L with battery disconnected; verify ~60Ω. Add/repair termination resistors if incorrect.
  8. Use an oscilloscope or CAN bus tool to confirm presence/absence of engine ECU CAN frames and to identify bus-off or dominant-state conditions. If ECU frames absent but other modules transmit, suspect ECU power/ECU internal fault.
  9. If immobiliser or gateway controls wake lines, verify wake/sleep signals and check immobiliser status; consult vehicle-specific wiring to confirm wake-up sequence.
  10. If wiring, power and grounds OK but no communication, consider reflashing or replacing the engine ECU per manufacturer guidance; consult TSBs or manufacturer service information before replacement.
  11. After repairs, clear codes and test-drive to confirm restoration of normal communications and that no new U-codes return.

Likely causes

  • Lost power to engine ECU (fuse, relay, wiring)
  • Broken/loose connector pins at engine ECU
  • CAN high/low wiring short to battery/ground or open circuit
  • Missing CAN termination (≈60 ohm) or single-ended bus voltage out of range
  • ECU in sleep/standby and not being woken by gateway or immobiliser

Fault status

⚠️ Status
No communication/signal received from engine management ECU on vehicle network. ECU messages expected by gateway/instrument cluster are missing or timed out.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 1.5-4.0 hours

Similar codes

U0100 U0073 U0140 U0121 U1110
Your experience will help others
+100 karma for a short comment :)
Keep it short and practical. Up to 500 characters.
Send to email

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