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Home >> Acura >> 2014 >> TSX Base, 4D Sedan >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> Electronic Throttle Control System (4-CYL) >> DTC Troubleshooting >> DTC P1658: ETCS Control Relay ON Malfunction
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DTC P1658: 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 to 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/PCM.

    NO  -Go to step 3.

  3. Turn the ignition switch to LOCK (0).
  4. Remove the ETCS control relay (A) from the under-hood fuse/relay box.
    Fig 1: Identifying ETCS Control Relay
    G07767823Courtesy 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/PCM connector A (49P).
  8. Check for continuity between ECM/PCM connector terminal A21 and body ground.
    Fig 2: Checking Continuity Between ECM/PCM Connector Terminal A21 And Body Ground
    G07767824Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  -Repair short in the wire between the ECM/PCM (A21) and the ETCS control relay, then go to step  13.

    NO  -Go to step 9.

  9. Disconnect ECM/PCM connector C (49P).
  10. Turn the ignition switch to ON (II).
  11. Measure the voltage between ECM/PCM connector terminal C1 and body ground.
    Fig 3: Measuring Voltage Between ECM/PCM Connector Terminal C1 And Body Ground
    G07767825Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

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

    NO  -Go to step  18.

  12. Turn the ignition switch to LOCK (0).
  13. Reconnect all connectors.
  14. Turn the ignition switch to ON (II).
  15. Reset the ECM/PCM with the HDS.
  16. Do the ECM/PCM idle learn procedure (see ECM/PCM 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/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.

  18. Turn the ignition switch to LOCK (0).
  19. Reconnect all connectors.
  20. Update the ECM/PCM if it does not have the latest software (see ECM/PCM UPDATE ), or substitute a known-good ECM/PCM (see SUBSTITUTING THE ECM/PCM ).
  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/PCM. If the ECM/PCM was updated, substitute a known-good ECM/PCM (see SUBSTITUTING THE ECM/PCM ), then recheck. If the ECM/PCM was substituted, go to step  1.

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

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