P0563
System Voltage High
Moderate· Fix soonDIY friendlyPowertrainGeneric, all makes
What it means
The ECU is seeing higher voltage than normal. The alternator is overcharging, which can damage the battery and electronics.
Is it safe to drive?
Drive short distances only. Overcharging can boil the battery and damage electronics.
Symptoms
- Battery warning light
- Very bright or flickering lights
- Battery hot or smelling of sulphur
Probable causes
Most likely first
- 1Faulty alternator voltage regulator
- 2Poor battery sense wire connection
- 3Jump-starting with a high-voltage charger
How to diagnose it
Work through these in order before buying parts
- 1Measure voltage with the engine running; above about 15 V is too high.
- 2Check alternator connections and the battery sense circuit.
- 3Check for technical service bulletins (TSBs) or software updates for your make and model; some codes have known factory fixes.
Common fixes
- Replace the alternator or regulator
- Repair the sense wiring
This information is general guidance for all makes. Exact causes, specifications and procedures vary by vehicle, so confirm with your service manual or a qualified mechanic before replacing parts.