Models: 2015 and later Nissan vehicles. Does not apply to Titan equipped with Cummins V8 Diesel engine.
Condition: The MIL is on with code DTC P0603 ECM BACK UP/CIRCUIT.
- Confirm that the battery voltage is 11 volts or more, with the ignition on and engine off.
- Erase DTC.
- Perform DTC confirmation steps in the service information.
- Confirm 1st trip DTC P0603 is not stored. P0603 is often the result of low battery voltage, discharged battery or battery terminal disconnections.
- The P0603 DTC may have been stored due to low battery voltage, discharged battery or battery terminal disconnections.
>Confirm the battery voltage is at least 11 volts, or more, with the ignition ON.
>While checking the battery voltage, make sure the battery cables are clean and tight.
- Resolve any low battery condition before proceeding. Repairs for a low battery condition are not covered by this bulletin.
- Connect a scan tool to the vehicle.
- Open C-III plus on the CONSULT PC.
- Turn the ignition “ON”, but Do Not Start the engine.
- Erase DTCs.
- Turn the ignition OFF.
- Turn the Ignition ON and wait for at least one second.
- Turn the ignition OFF and wait for at least 10 seconds.
- Repeat step 7 and step 8 ten times and then proceed to step 10.
- Turn ignition ON.
- Is P0603 currently stored as a 1st trip DTC?
>NO: Service Procedure is complete.
>YES: Refer to the service information section “Engine Control System” for further diagnostic information.
Courtesy of Mitchell1