P0602
Control Module Programming Error
Severeelectrical
Overview
The P0602 code indicates an control module programming error fault has been detected in the vehicle's electrical system. This code relates to the internal control module, charging system, or starter circuit. Electrical issues at the PCM level can cause widespread vehicle operation problems and should be diagnosed thoroughly.
Symptoms
- Electrical accessories malfunctioning
- Check Engine Light (MIL) illuminated
- Vehicle going into limp mode or reduced power
- Vehicle not starting or cranking slowly
Common Causes
- Low battery voltage or failing battery
- Failed relay or fuse
- Faulty engine control module (ECM/PCM)
- Water damage to electrical connectors
Diagnosis Steps
- 1Connect an OBD-II scanner and read all stored trouble codes and freeze frame data
- 2Check battery voltage and charging system output with a multimeter
- 3Inspect wiring and connectors related to the trouble code
- 4Test circuit voltage, ground, and resistance with a multimeter
- 5Check related fuses and relays
Estimated Repair Cost
$75 — $400
Cost varies by vehicle, location, and repair shop. Includes parts and labor.
Commonly Affected Vehicles
Hyundai SonataGMC CanyonRam 1500Chevrolet Colorado
Related Codes
More Electrical Codes
B0001Driver Frontal Airbag Deployment Loop Circuit Open
CriticalB0002Driver Frontal Airbag Deployment Loop Circuit Short to Ground
CriticalB0003Driver Frontal Airbag Deployment Loop Circuit Short to Battery
CriticalB0004Driver Frontal Airbag Deployment Loop Resistance Too High
CriticalB0005Driver Frontal Airbag Deployment Loop Resistance Too Low
CriticalB0006Passenger Frontal Airbag Deployment Loop Circuit Open
CriticalFrequently Asked Questions
Electrical codes can be challenging because they often involve intermittent issues. A thorough inspection of wiring, connectors, and grounds with a multimeter is essential for accurate diagnosis.