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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 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 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 ETCS control relay and the-PCM. ■

  4. Turn the ignition switch to LOCK (0).
  5. Check the No. 21 DBW (THROTTLE ACTUATOR CONTROL) (15A) fuse in the under-hood fuse/relay box.

    Is the fuse OK? 

    YES  - Go to step  6.

    NO  - Go to step  17

  6. Remove the ETCS control relay (F) from the under-hood fuse/relay box.
    7. Fig 1: Identifying ETCS Control Relay
    G05961292Courtesy of AMERICAN HONDA MOTOR CO., INC.
  7. Test the ETCS control relay (see POWER RELAY TEST ).

    Is the ETCS control relay OK? 

    YES  - Go to step  8.

    NO  - Replace the ETCS control relay, then go to step  23

  8. Turn the ignition switch to ON (II).
  9. Measure the voltage between ETCS control relay 4P connector terminal No. 4 and body ground.

    10. Is there battery voltage? 

    YES  - Go to step  10.

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

    Fig 2: Checking Voltage Between ETCS Control Relay 4P Connector Terminal No. 4 & Body Ground
    G05961293Courtesy of AMERICAN HONDA MOTOR CO., INC.
  10. Measure the voltage between ETCS control relay 4P connector terminal No. 1 and body ground.

    11. Is there battery voltage? 

    YES  - Go to step  11.

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

    Fig 3: Checking Voltage Between ETCS Control Relay 4P Connector Terminal No. 1 & Body Ground
    G05961294Courtesy of AMERICAN HONDA MOTOR CO., INC.
  11. Turn the ignition switch to LOCK (0).
  12. Jump the SCS line with the HDS.
  13. Disconnect PCM connector C (49P).
  14. Check for continuity between ETCS control relay 4P connector terminal No. 2 and PCM connector terminal C4.

    15. Is there continuity? 

    YES  - Go to step  15.

    NO  - Repair open in the wire between the PCM (C4) and the ETCS control relay, then go to step  23

    Fig 4: Checking Continuity Between ETCS Control Relay 4P Connector Terminal No. 2 & PCM Connector Terminal C4
    G05961295Courtesy of AMERICAN HONDA MOTOR CO., INC.
  15. Disconnect PCM connector A (49P).
  16. Check for continuity between ETCS control relay 4P connector terminal No. 3 and PCM connector terminal A29.
    17. Fig 5: Checking Continuity Between ETCS Control Relay 4P Connector Terminal No. 3 And PCM Connector Terminal A29
    G05961296Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  - Go to step  28

    NO  - Repair open in the wire between the PCM (A29) and the ETCS control relay, then go to step  23

  17. Remove the ETCS control relay (F) from the under-hood fuse/relay box.
    18. Fig 6: Identifying ETCS Control Relay
    G05961297Courtesy of AMERICAN HONDA MOTOR CO., INC.
  18. Jump the SCS line with the HDS.
  19. Disconnect PCM connector C (49P).
  20. Check for continuity between PCM connector terminal C4 and body ground.

    21. Is there continuity? 

    YES  - Repair short in the wire between the PCM (C4) and the ETCS control relay, then go to step  23

    NO  - Go to step  21.

    Fig 7: Checking Continuity Between PCM Connector Terminal C4 & Body Ground
    G05961298Courtesy of AMERICAN HONDA MOTOR CO., INC.
  21. Check for continuity between ETCS control relay 4P connector terminal No. 1 and body ground.
    Fig 8: Checking Continuity Between ETCS Control Relay 4P Connector Terminal No. 1 & Body Ground
    G05961299Courtesy of AMERICAN HONDA MOTOR CO., INC.

    22. Is there continuity? 

    YES  - Replace the under-hood fuse/relay box (see REMOVAL AND INSTALLATION ), then go to step  23

    NO  - Go to step  28

  22. Turn the ignition switch to LOCK (0).
  23. Reconnect all connectors.
  24. Turn the ignition switch to ON (II).
  25. Reset the PCM with the HDS.
  26. Do PCM IDLE LEARN PROCEDURE .
  27. Check for Pending or Confirmed DTCs or DTCs with the HDS.

    Is DTC P1659 indicated? 

    YES  - Check for poor connections or loose terminals at the ETCS control relay and the PCM, then go to step  1

    NO  - Troubleshooting is complete. If any other Pending or Confirmed DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting. ■

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

Is DTC P1659 indicated? 

YES  - Check for poor connections or loose terminals at the ETCS control relay 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 Pending or Confirmed DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting. ■

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