P0603 Mercedes-Benz ECM Power Supply Circuit
Possible causes
– Loose or poor battery terminal connection
– Low battery charge
– ECM power supply circuit is open or shorted
– ECM Programing
– Faulty ECM
– Low battery charge
– ECM power supply circuit is open or shorted
– ECM Programing
– Faulty ECM
Tech description
Start by charging the vehicles battery and clean terminal, once the battery is charged and the terminals are clean and secure, erase code. If the code comes back ON you may have to reprogram or replaced ECM
What about the obd code?
Indicates the ECM has experienced an internal memory fault.
Symptoms
– Engine Light ON (or Service Engine Soon Warning Light)
– Engine may not start
– Engine may not start
P0603 Mercedes-Benz Description
Battery voltage is supplied to the ECM even when the ignition switch is turned OFF for the ECM memory function of the DTC memory, the air-fuel ratio feedback compensation value memory, the idle air volume learning value memory, etc.
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,