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DTC P1659: ETCS Control Relay OFF Malfunction

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 ON (II).
  2. Clear the DTC with the HDS.
  3. Check for Temporary DTCs or DTCs with the HDS.

    Is DTC P1659 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 under-hood fuse/relay box (ETCS control relay) and the PCM.

  4. Turn the ignition switch OFF.
  5. Check the No. 10 THROTTLE ACTUATOR CONTROL (DBW+) (15 A) fuse in the under-hood fuse/relay box.

    Is the fuse OK? 

    YES  - Go to step 6.

    NO  - Go to step  14.

  6. Test the ETCS control relay in the under-hood fuse/ relay box (see POWER RELAY TEST ).

    Is the ETCS control relay OK? 

    YES  - Go to step 7.

    NO  - Replace the relay control module (under-hood fuse/relay box) (see REMOVAL AND INSTALLATION ), then go to step  22.

  7. Jump the SCS line with the HDS.
  8. Disconnect PCM connector C (49P).
  9. Disconnect the under-hood fuse/relay box connector H (9P).
  10. Check for continuity between under-hood fuse/ relay box connector H (9P) terminal No. 7 and PCM connector terminal C4.
    Fig 1: Identifying Continuity Between Under-Hood Fuse/ Relay Box Connector H (9P) Terminal No. 7 And PCM Connector Terminal C4
    G05485152Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  - Go to step 11.

    NO  - Repair open in the wire between the PCM (C4) and the under-hood fuse/relay box, then go to step  22.

  11. Disconnect PCM connector A (49P).
  12. Disconnect under-hood fuse/relay box connector E (14P).
  13. Check for continuity between under-hood fuse/ relay box connector E (14P) terminal No. 14 and PCM connector terminal A29.
    Fig 2: Identifying Continuity Between Under-Hood Fuse/ Relay Box Connector E Terminal No. 14 And PCM Connector Terminal A29
    G05485153Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  - Go to step  27.

    NO  - Repair open in the wire between the PCM (A29) and the under-hood fuse/relay box, then go to step  22.

  14. Jump the SCS line with the HDS.
  15. Disconnect PCM connector C (49P).
  16. Disconnect the under-hood fuse/relay box connector H (9P).
  17. Check for continuity between PCM connector terminal C4 and body ground.
    Fig 3: Identifying Continuity Between PCM Connector Terminal C4 And Body Ground
    G05485154Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  - Repair short in the wire between the PCM (C4) and the under-hood fuse/relay box, then go to step  22.

    NO  - Go to step 18.

  18. Install the under-hood fuse/relay box connector H (9P), and replace the No. 10 THROTTLE ACTUATOR CONTROL (DBW+) fuse in the under-hood fuse/ relay box.
  19. Turn the ignition switch ON (II).
  20. Measure voltage between PCM connector terminal C4 and body ground.
    Fig 4: Identifying Voltage Between PCM Connector Terminal C4 And Body Ground
    G05485155Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

    YES  - Go to step  27.

    NO  - Replace the right side engine compartment wire harness. Also replace the No. 10 THROTTLE ACTUATOR CONTROL (DBW+) fuse in the under-hood fuse/relay box, then go to step 21.

  21. Turn the ignition switch OFF.
  22. Reconnect all connectors.
  23. Turn the ignition switch ON (II).
  24. Reset the PCM with the HDS.
  25. Do the PCM idle learn procedure (see PCM IDLE LEARN PROCEDURE ).
  26. Check for Temporary DTCs or DTCs with the HDS.

    Is DTC P1659 indicated? 

    YES  - Check for poor connections or loose terminals at the under-hood fuse/relay box and the PCM, then go to step  1.

    NO  - Troubleshooting is complete. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTCs troubleshooting.

  27. Reconnect all connectors.
  28. Update the PCM if it does not have the latest software (see PCM UPDATE ), or substitute a known-good PCM (see SUBSTITUTING THE PCM ).
  29. Check for Temporary DTCs or DTCs with the HDS.

    Is DTC P1659 indicated? 

    YES  - Check for poor connections or loose terminals at the under-hood fuse/relay box and the PCM. If the PCM was updated, substitute a known-good PCM (see SUBSTITUTING THE PCM ), then recheck. If the PCM was substituted, go to step  1.

    NO  - If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see PCM REPLACEMENT ). If any other Temporary DTCs or DTCs are indicated, go to the indicated DTCs troubleshooting.