P0685 Mercedes-Benz 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)
– 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 Mercedes-Benz Description
The Engine Control Module (ECM) has detected that the ECM remains powered up after the ignition key has been turned off
Mercedes-Benz Vehicle:Mercedes-Benz C-Class,Mercedes-Benz CL-Class,Mercedes-Benz CLK-Class,Mercedes-Benz CLS-Class,Mercedes-Benz E-Class,Mercedes-Benz G-Class,Mercedes-Benz GL-Class,Mercedes-Benz GLK-Class,Mercedes-Benz M-Class,Mercedes-Benz R-Class,Mercedes-Benz S-Class,Mercedes-Benz SL-Class,Mercedes-Benz SLK-Class,Mercedes-Benz SLS-Class,Mercedes-Benz Sprinter 2500,Mercedes-Benz Sprinter 3500,