Advanced Diagnostics

DTC P0685: Engine Control Module (ECM)/Powertrain Control Module (PCM) Power Control Circuit Malfunction




General Description
If something is wrong in the engine control module (ECM)/powertrain control module (PCM) that causes the PGM-FI main relay (FI MAIN) to turn OFF before the ignition switch is turned OFF, the ECM/PCM detects a malfunction and a DTC is stored.




Monitor Execution, Sequence, Duration, DTC Type, OBD Status




Enable Conditions

Malfunction Threshold
The PGM-FI main relay (FI MAIN) is turned OFF before the ignition switch is turned OFF, and the ECM/PCM stops operating.

Diagnosis Details

Conditions for illuminating the MIL
When another MIL-illuminating failure has already been detected: When a malfunction is detected, the MIL comes on and the DTC and the freeze frame data are stored in the ECM/PCM memory.

When another MIL-illuminating failure has not yet been detected: When a malfunction is detected during the first drive cycle, a Temporary DTC is stored in the ECM/PCM memory. If the malfunction recurs during the next (second) drive cycle, the MIL comes on and the DTC and the freeze frame data are stored.

Conditions for clearing the MIL
The MIL will be cleared if the malfunction does not recur during three consecutive trips in which the diagnostic runs.

The MIL, the DTC, and the freeze frame data can be cleared by using the scan tool Clear command or by disconnecting the battery.