P0563
System Voltage High
Battery / charging system voltage seen by the ECU exceeds the upper threshold (typically around 16 V). Caused by a failing voltage regulator inside the alternator. Sustained over-voltage can damage other electronics.
- Check engine light: Yes
- Emissions related: No
- Repair difficulty: medium
Common causes
Ordered by how often each turns out to be the cause.
- Voltage regulator failedCommon
- Alternator overchargingPossible
Parts involved
- Alternator
- Voltage Regulator
P0563 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.