U0120
Lost Communication With Starter / Generator Control Module
Severity: HIGH
Symptoms
- Problems starting the engine
- Check Engine Light Is On
- Disabling the start-stop system
- Low battery
- Other related errors appear
Causes
- Open or short circuit in the communication circuit
- Starter/Generator Control Module Malfunction
- Module power problems
- Wiring harness damage
- Software errors in the ECU
How to Fix
- Check the integrity of the wiring harness and connectors
- Check fuses and relays associated with the module
- Diagnose the starter/generator control module
- Update ECU software if necessary
- Replace the faulty module if the breakdown is confirmed