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DTC P1658: Electronic Throttle Control System (ETCS) Control Relay ON 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. Do the ETCS TEST in the INSPECTION MENU with the HDS.

    Is the RELAY circuit OK? 

    YES  - Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the ETCS control relay and the ECM.

    NO  - Go to step 3.

  3. Turn the ignition switch OFF.
  4. Remove the ETCS control relay (F) from the under-hood fuse/relay box.
    Fig 1: Identifying ETCS Control Relay
    G04665999Courtesy of AMERICAN HONDA MOTOR CO., INC.
  5. Test the ETCS control relay (see POWER RELAY TEST ).

    Is the ETCS control relay OK? 

    YES  - Go to step 6.

    NO  - Replace the ETCS control relay, then go to step  13.

  6. Jump the SCS line with the HDS.
  7. Disconnect ECM connector A (44P).
  8. Check for continuity between ECM connector terminal A20 and body ground.
    Fig 2: Checking Continuity Between ECM Connector Terminal A20 And Body Ground
    G04666000Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  - Repair short in the wire between the ECM (A20) and the ETCS control relay, then go to step  13.

    NO  - Go to step 9.

  9. Disconnect ECM connector C (44P).
  10. Turn the ignition switch ON (II).
  11. Measure voltage between ECM connector terminal C1 and body ground.
    Fig 3: Measuring Voltage Between ECM Connector Terminal C1 And Body Ground
    G04666001Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

    YES  - Repair short to power in the wire between the ECM (C1) and the ETCS control relay, then go to step 12.

    NO  - Go to step  18.

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

    Is DTC P1658 indicated? 

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

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

  18. Turn the ignition switch OFF.
  19. Reconnect all connectors.
  20. Update the ECM if it does not have the latest software (see ECM UPDATE ), or substitute a known-good ECM (see SUBSTITUTING THE ECM ).
  21. Check for Pending or Confirmed DTCs with the HDS.

    Is DTC P1658 indicated? 

    YES  - Check for poor connections or loose terminals at the ETCS control relay and the ECM. If the ECM was updated, substitute a known-good ECM (see SUBSTITUTING THE ECM ), then recheck. If the ECM was substituted, go to step  1.

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

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