When IG KEY OFF signal is imputted to ECM. ECM stops injector operation andn engine turns OFF. Then, After-run(turning off process of ECM intermal system) is performed in order to shut system down. During this process, if main relay power supply is cut too late or power supply is cut too early before After-run process completes, ECM detect main relay error and P0685 is set.
Item | Detecting Condition | Possible Cause | ||
DTC Strategy |
•
Voltage monitoring |
•
Engine Control relay circuit
•
Engine Control relay component | ||
Enable Conditions |
•
IG KEY "ON" | |||
Threshold Value |
•
When main relay respond to IG KEY - ON/OFF signal too fast or slow | |||
Diagnostic Time |
•
50msec | |||
Fail Safe | Fuel Cut | NO | ||
EGR Off | NO | |||
Fuel Limit | NO | |||
Check Lamp | NO | |||
