DTC U0155: F-CAN Malfunction (ECM/PCM- Gauge Control Module)

2008 Honda Civic Si, 4D SedanSECTION DTC U0155: F-CAN Malfunction (ECM/PCM- Gauge Control Module)
WARNING: This page is about a different variant/trim than selected.
NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).
  1. Turn the ignition switch to ON (II).
  2. Clear the DTC with the HDS.
  3. Check for Pending or Confirmed DTCs with the HDS.

    Is DTC U0155 indicated? 

    YES  -Go to step 4.

    NO  -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the gauge control module (tach) and the ECM/PCM.

  4. Check for body electrical DTCs in the DTCs MENU with the HDS.

    Is DTC B1168, B1169, and/or B1178 indicated? 

    YES  -Go to step 5.

    NO  -Do the gauge control module (tach) input test (see GAUGE CONTROL MODULE (TACH) INPUT TEST ).

  5. Turn the ignition switch to LOCK (0).
  6. Jump the SCS line with the HDS.
  7. Remove the gauge control module (tach) (see TACHOMETER ).
  8. Disconnect ECM/PCM connector A (44P).
  9. Check for continuity between ECM/PCM connector terminal A36 and gauge control module (tach) 36P connector terminal No. 1.
    Fig 1: Checking Continuity Between ECM/PCM Connector Terminal A36 And Body Ground
    G00492617Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  -Go to step 10.

    NO  -Repair open in the wire between the ECM/PCM (A36) and gauge control module (tach), then go to step 11.

  10. Check for continuity between ECM/PCM connector terminal A37 and gauge control module (tach) 36P connector terminal No. 19.
    Fig 2: Checking Continuity Between ECM/PCM Connector Terminal A37
    G00492618Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  -Substitute a known-good gauge control module (tach), then go to step 11 and recheck. If DTC U0155 is not indicated after substitution, replace the original gauge control module (tach), then go to step 11.

    NO  -Repair open in the wire between the ECM/PCM (A37) and the gauge control module (tach), then go to step 11.

  11. Reconnect all connectors.
  12. Turn the ignition switch to ON (II).
  13. Reset the ECM/PCM with the HDS.
  14. Do the ECM/PCM idle learn procedure (see ECM/PCM IDLE LEARN PROCEDURE ).
  15. Check for Pending or Confirmed DTCs with the HDS.

    Is DTC U0155 indicated? 

    YES  -Check for poor connections or loose terminals at the gauge control module (tach) and the ECM/PCM, then go to step  1.

    NO  -Troubleshooting is complete. If any other Pending or Confirmed DTCs are indicated, go to the INDICATED DTC'S TROUBLESHOOTING .

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • You smell fuel, burning insulation, or see smoke.
  • Brakes feel soft, pull hard to one side, or make grinding noises.
  • The engine overheats, stalls repeatedly, or misfires under load.
  • You are missing required tools, torque specs, or safe lifting equipment.
  • You are not confident in the next step or safety outcome.