The computer sees battery voltage below its normal range. The driver may notice dim lights, hard starting or several warning lights.
Likely causes, most common first
- Weak alternator
- Worn battery
- Loose or corroded battery terminals
- Slipping drive belt
Parts usually involved
- Alternator
- Battery
- Battery terminals
- Drive belt
Test before you replace
Measure battery voltage at rest and with the engine running under load, then test voltage drop on the main cables.
General guidance for generic OBD2 codes. Always follow the maker's procedure for the car in front of you.