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Home >> Acura >> 2012 >> TL Base >> Repair and Diagnosis >> Engine Performance >> System >> PGM-FI System >> DTC Troubleshooting >> DTC P0685: ECM/PCM Power Control Circuit/Internal Circuit Malfunction
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DTC P0685: ECM/PCM Power Control Circuit/Internal Circuit Malfunction

NOTE:
  • Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).
  • If the problem doesn't return after you clear the DTC, or if this DTC is stored intermittently, check for loose terminals at the IGP line connectors before replacing the ECM/PCM.
  1. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
  2. Clear the DTC with the HDS.
  3. Start the engine, and let it idle for 30 seconds.
  4. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
  5. Start the engine, and let it idle for 30 seconds.
  6. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
  7. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
  8. Check for Pending or Confirmed DTCs with the HDS.

    Is DTC P0685 indicated? 

    YES  - Go to step 9.

    NO  - Intermittent failure, the system is OK at this time. ■

  9. 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 ).
  10. Start the engine, and let it idle for 30 seconds.
  11. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
  12. Start the engine, and let it idle for 30 seconds.
  13. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
  14. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
  15. Check for Pending or Confirmed DTCs with the HDS.

    Is DTC P0685 indicated? 

    YES  - If the ECM/PCM was updated, substitute a known-good ECM/PCM (see SUBSTITUTING THE ECM/PCM ), then go to step  10. 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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