DTC P0685 [MZI-3.7]

id0102d2956100

DTC P0685

ECM/PCM power relay control circuit/open

DETECTION CONDITION

•  This DTC sets when the ignition switch position run circuit indicates the key is in the off, ACC, or LOCK position, and the amount of time the PCM remains powered through the PCM power relay exceeds a predetermined amount of time.

POSSIBLE CAUSE

•  Short to ground circuit between main relay No.1 terminal A and PCM terminal 1BM

•  Main relay No.1 malfunction

•  PCM malfunction

DTC P0685	ECM/PCM power relay control circuit/open
DETECTION CONDITION	• This DTC sets when the ignition switch position run circuit indicates the key is in the off, ACC, or LOCK position, and the amount of time the PCM remains powered through the PCM power relay exceeds a predetermined amount of time.
POSSIBLE CAUSE	• Short to ground circuit between main relay No.1 terminal A and PCM terminal 1BM • Main relay No.1 malfunction • PCM malfunction

Diagnostic procedure

STEP	INSPECTION		ACTION
1	VERIFY FREEZE FRAME DATA HAS BEEN RECORDED • Has FREEZE FRAME DATA been recorded?	Yes	Go to the next step.
1		No	Record FREEZE FRAME DATA on the repair order, then go to the next step.
2	VERIFY RELATED SERVICE INFORMATION AVAILABILITY • Verify related Service Information availability. • Is any related Service Information available?	Yes	Perform repair or diagnosis according to the available Service Information. • If the vehicle is not repaired, go to the next step.
2		No	Go to the next step.
3	INSPECT MAIN RELAY NO.1 CONTROL CIRCUIT FOR SHORT TO GROUND • Turn the ignition switch off. • Inspect for continuity between main relay No.1 terminal A (wiring harness-side) and body ground. • Is there continuity?	Yes	Repair or replace suspected part, then go to Step 5.
3		No	Go to the next step.
4	INSPECT FOR CORRECT PCM OPERATION • Disconnect all the PCM connectors. • Visually inspect for: ― Pushed out pins ― Corrosion • Connect all the PCM connectors and verify that they seat correctly. • Retrieve DTCs using the M-MDS. • Is the PENDING CODE for this DTC present?	Yes	Go to the next step.
4		No	The system is correctly. Go to the next step.
5	VERIFY TROUBLESHOOTING OF DTC P0685 HAS BEEN COMPLETED • Verify that all disconnected connectors reconnected. • Clear the DTC from the PCM memory using the M-MDS. • Perform the “KOEO or KOER self-test” using the M‐MDS. (See KOEO/KOER SELF TEST [MZI-3.7].) • Is the PENDING CODE for the DTC present?	Yes	Replace the PCM, then go to the next step. (See PCM REMOVAL/INSTALLATION [MZI-3.7].)
5		No	Go to the next step.
6	VERIFY AFTER REPAIR PROCEDURE • Perform the “AFTER REPAIR PROCEDURE”. (See AFTER REPAIR PROCEDURE [MZI-3.7].) • Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE [MZI-3.7].)
6		No	Troubleshooting completed.