P0563: System voltage high
Stop driving. Get it towed or fixed first.
Can I drive with P0563?
No, stop driving safely as soon as possible. Alternator voltage regulator is overcharging; risks frying vehicle computers and boiling battery.
What does P0563 mean?
P0563 stands for System Voltage High.
Symptoms you may notice
- Abnormally bright or pulsating headlights
- Sulfur or rotten egg smell from boiling battery acid
- Electrical warning lights popping up across dashboard
How much does it cost to fix?
Repair costs for code P0563 depend on the specific underlying root cause, ranging from simple DIY checks to component replacement. The table below lists the most common causes and rough price ranges in USD:
- Faulty internal alternator voltage regulator
- Loose alternator sense wire connection
- Corroded engine-to-chassis ground strap
- Dead cell in battery causing regulator over-spike
What to do next
- Stop driving as soon as safely possible to prevent burning out electronic control modules.
- Measure running voltage across the battery posts (if above excessive charging voltage, do not drive).
- Replace the alternator assembly.
Last updated: October 2026
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General guidance only, not a professional diagnosis. If the check-engine light is flashing, or the car is running rough, overheating or losing power, stop driving and get help.
About this code
Code P0563 indicates dangerous overvoltage (typically exceeding excessive charging voltage). Overcharging can boil battery acid, burst headlamp bulbs, and destroy the expensive electronic modules (ECU, ABS, BCM) running your car. Shut off the car and tow it for an alternator replacement.