All trouble codes → Charging system & system voltage codes
Charging system & system voltage codes
These codes watch the voltage the electrical system runs on. Too low usually means a weak battery, a failing alternator, or corroded terminals and grounds; too high points at the voltage regulator. A quick battery and charging-output test sorts it out — at rest the battery should read 12.4–12.7 V, and 13.5–14.8 V with the engine running.
Diagnose before extended driving.
Common causes
- Weak battery
- Generator/alternator fault
- Corroded battery terminals or grounds
First checks
- Battery at rest should be 12.4–12.7 V; running 13.5–14.8 V
- Load-test the battery and check charging output
System: Vehicle speed, idle control & auxiliary inputs. This is general guidance for the generic OBD-II codes in this group; always confirm against the service information for your specific vehicle.
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