P0563
System Voltage High
Charging / vehicle power
Generic OBD-II
High
What it means
P0563 means the ECM sees the vehicle's electrical system voltage staying above its normal range — the system is overcharging. It usually points to a faulty voltage regulator or alternator, or a bad ground that misleads the charging control. Prolonged high voltage can cook the battery and damage electronics, so have the charging system checked before driving much.
High
Can I keep driving? Short trips only — persistent overcharging can damage the battery and electronics; have the charging system checked before driving much.
Common symptoms
What you'll notice
- Check-engine light on
- Voltage/battery gauge reads high or fluctuates
- Headlights or dash lights unusually bright, sometimes flickering
- Battery runs hot, swells, or fails early from overcharging
Common causes
Most likely first
- Faulty voltage regulator (usually integral to the alternator) — most commonLikely
- Failing alternator overcharging the systemCommon
- Poor ground or high-resistance connection fooling the regulator's sense circuitCommon
- Wiring fault in the charging-system sense lineLess often
- Faulty ECM/PCM voltage sensing (rare)Less often
How to diagnose & fix
Work through it in order
- Measure charging voltage at the battery with the engine running — a healthy system holds roughly 13.5–14.7V; well above that confirms overcharging.
- Inspect and clean the battery terminals and engine/body grounds; a bad ground is a common cause of false-high voltage.
- Check the alternator sense/wiring connections for damage or corrosion.
- Test the alternator and its internal voltage regulator; replace the alternator if the regulator is faulty.
- Clear the code and re-measure voltage to confirm the repair.
FAQ
Quick answers
Is it safe to drive with P0563?+
Keep it short. Sustained overcharging can boil the battery and stress sensitive electronics. Get the charging voltage checked promptly.
Can I just clear P0563?+
It returns while the voltage stays high. Fix the regulator, ground, or wiring first, then clear and verify with a voltage reading.
Related codes
Often seen with P0563
Read & clear P0563 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX