P0685 Cadillac Electronic Control Module Power Control Circuit Malfunction

P0685 Cadillac Electronic Control Module Power Control Circuit Malfunction

Possible causes
– Faulty Engine Control Module (ECM) power relay
– ECM power relay harness is open or shorted
– ECM power relay circuit poor electrical connection
– Faulty (ECM)
Tech description
Check all the ECM fuses, if the fuses are OK try replacing the ECM relay.
Symptoms
– Engine Light ON (or Service Engine Soon Warning Light)
P0685 Cadillac Description

The Engine Control Module (ECM) has detected that the ECM remains powered up after the ignition key has been turned off

Cadillac Vehicle:Cadillac CTS Coupe, Cadillac CTS-V Coupe , Cadillac Eldorado , Cadillac Escalade EXT , Cadillac ATS , Cadillac CTS , Cadillac CTS Sedan , Cadillac CTS Sport Sedan , Cadillac CTS-V , Cadillac CTS-V Sedan , Cadillac Catera , Cadillac DTS , Cadillac DeVille , Cadillac STS-V , Cadillac STS , Cadillac Seville , Cadillac XTS , Cadillac XLR , Cadillac XLR Platinum , Cadillac Escalade , Cadillac SRX