DTC Troubleshooting: P0685 (135)

DTC P0685:

ECM/PCM Power Control Circuit/Internal Circuit Malfunction

• Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information.
• If the problem doesn't return after you clear the DTC, or it this DTC is stored intermittently, check for loose terminals at the IGP line connectors before replacing the ECM/PCM.

1.	Turn the ignition switch ON (II).

2.	Clear the DTC with the HDS.

3.	Start the engine, then let it idle for 30 seconds.

4.	Turn the ignition switch OFF.

5.	Start the engine, then let it idle for 30 seconds.

6.	Turn the ignition switch OFF.

7.	Turn the ignition switch ON (II).

8.

Check for Temporary DTCs or DTCs with the HDS. Is DTC P0685 indicated? YES - Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM, then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM.n NO - Intermittent failure, system is OK at this time.n