685

Possible Causes

• •Faulty ECM
• •Faulty Relay
• •Faulty Relay connection/wiring
• •Faulty harness (open-circuit)
• •Faulty power relay fuse
• •Incorrect battery voltage to and from the power relay

Suggested Actions

1. 1Check for battery voltage to and from the power relay and repair as needed
2. 2Check power relay fuse and repair as needed
3. 3Disconnect the wire harness header from the ECM, carefully remove the yellow lock from the header at the device output terminal, and check the resistance between the Relay output at the ECM header and at the relay (Do not insert a probe or object into the terminals to avoid spreading the pins).
4. 4Locate VRelay voltage on EDIS RawVolts page with Key ON, Engine On
5. 5Perform On-Board (OBD) System Check
6. 6Perform the On-Board (OBD) System Check.
7. 7Refer to diagnostics for the set fault, repair and retest
8. 8Remove the relay from the fuse block/relay module and use a DMM to measure the voltage potential from the relay output to ground while the engine is trying to crank.
9. 9Verify if DTC 685 is active during Key ON, Engine Cranking (System Mode = 'Cranking').
10. 10With Key Off, connect a test lamp to Vbat and Relay output. Turn Key On (Engine Off, System Mode = 'Stopped', External power Test Mode = 'All On') and check if the test lamp stays lit.

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