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DTC B12F0: Power Control Unit Lost Communication With Electric Steering Lock

NOTE: If you are troubleshooting multiple DTCs, be sure to follow the instructions in B- CAN System Diagnosis Test Mode A (see TROUBLESHOOTING - B- CAN SYSTEM DIAGNOSIS TEST MODE A ).
  1. Clear the DTCs with the HDS.
  2. Do this procedure 10 times: Press the engine start/stop button to select the OFF, ACC, ON, and OFF mode.
  3. Check for DTCs with the HDS.

    Is DTC B12F0 indicated? 

    YES  - Go to step 4.

    NO  - Intermittent failure, the system is OK at this time. Check for loose or poor connections.

  4. Measure the voltage between body ground and electric steering lock 12P connector terminal No. 4.
    Fig 1: Measuring Voltage Between Body Ground And Electric Steering Lock 12P Connector Terminal No. 4
    G08067660Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

    YES  - Go to step 5.

    NO  - Blown No. 12 (10 A) fuse in the passenger's under- dash fuse/relay box, repair an open or high resistance in the wire.

  5. Measure the voltage between body ground and electric steering lock 12P connector terminal No. 12.
    Fig 2: Measuring Voltage Between Body Ground And Electric Steering Lock 12P Connector Terminal No. 1
    G08067661Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there less than 0.2 V? 

    YES  - Go to step 6.

    NO  - Repair an open or high resistance in the wire or poor ground (G405).

  6. Press the engine start/stop button to select the OFF mode.
  7. Disconnect these items:
    • Electric steering lock 12P connector
    • Power control unit connector C (36P)
    • Remote slot control unit 40P connector
    • Keyless access control unit connector B (32P)
  8. Check for continuity between body ground and electric steering lock 12P connector terminal No. 1.
    Fig 3: Checking Continuity Between Body Ground And Electric Steering Lock 12P Connector Terminal No. 1
    G08067662Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  - Repair a short to ground in the wire.

    NO  - Go to step 9.

  9. Check for continuity between electric steering lock 12P connector terminal No. 1 and power control unit connector C (36P) terminal No. 2.
    Fig 4: Checking Continuity Between Electric Steering Lock 12P Connector Terminal No. 1 And Power Control Unit Connector C (36P) Terminal No. 2
    G08067663Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  - Go to step 10.

    NO  - Repair an open or high resistance in the wire.

  10. Reconnect these items:
    • Electric steering lock 12P connector
    • Power control unit connector C (36P)
    • Remote slot control unit 40P connector
    • Keyless access control unit connector B (32P)
  11. Do the battery terminal disconnect procedure (see BATTERY TERMINAL DISCONNECTION AND RECONNECTION ).
  12. Wait for at least 10 seconds to clear the DTCs.
  13. Do the battery terminal reconnection procedure (see BATTERY TERMINAL DISCONNECTION AND RECONNECTION ).
  14. Turn the keyless access system mode switch ON.
  15. If necessary, remove the remote from the remote slot.
  16. Press the engine start/stop button to select the ON mode, then select the OFF mode.
  17. Insert the remote into the remote slot.
  18. Press and hold the engine start/stop button to select the ON mode.

    Does the mode change to ON? 

    YES  - Go to step 19.

    NO  - Go to step  22.

  19. Clear the DTCs with the HDS.
  20. Do this procedure 10 times: Press the engine start/stop button to select the OFF, ACC, ON, and OFF mode.
  21. Check for DTCs with the HDS.

    Is DTC B12F0 indicated? 

    YES  - Replace the electric steering lock (see STEERING LOCK REPLACEMENT ).

    NO  - Intermittent failure, the system is OK at this time. Check for loose or poor connections.

  22. Connect the HDS to the data link connector (DLC).
  23. Select COMMUNICATION STATUS in the INSPECTION MENU with the HDS.
  24. Check the value of STATUS with ESL, STATUS with KEYLESS ACCESS CONTROL UNIT, and STATUS with SLOT with the HDS.
      HDS Description Value
    Status with ESL MTR CUT1 (Cont) Status 1
    MTR CUT2 (IG) Status 1
    IG1 Input State of ESL 1
    MTRCONT Status of ESL 1
    ESL Motor Status 1
    Switch D detection for Unlock Status 1
    Switch C detection for Unlock Status 1
    Switch B detection for Unlock Status 1
    Status with KEYLESS ACCESS CONTROL UNIT FOR KEY Authentication Result 1
    Status with SLOT FOR KEY Authentication Result 1

    Are only values of status with ESL 1? 

    YES  - Replace the electric steering lock (see STEERING LOCK REPLACEMENT ).

    NO  - Replace the power control unit (see CONTROL UNIT INPUT TEST  ).