P0563 P0xxx · Powertrain (P) High severity
System Voltage High
The ECU sees charging voltage above roughly 16 V. Overcharging boils the battery and can damage sensitive electronics across the vehicle.
Severity guidance: High — stop driving and diagnose now; risk of further damage
Symptoms you will notice
- Bulbs burning out repeatedly
- Battery boiling or swollen case
- Warning lights across modules
- Burnt electronics smell
Common causes
Ordered from most to least likely — start at the top.
- 1 Failed voltage regulator inside the alternator
- 2 Faulty battery temperature or voltage sensing
- 3 Bad earth or sensing wire
- 4 Aftermarket charging modifications
How to diagnose it
Cheapest and least invasive first — most of these codes are not a parts problem.
- ✓ Measure battery voltage with the engine running — above 15.5 V confirms overcharging.
- ✓ Check the alternator's sensing wire and main earth connections.
- ✓ Load-test the battery; a failing battery can also confuse smart regulators.
- ✓ Inspect for aftermarket audio or lighting wiring that affects sensing.
Repair options
- Replace or repair the alternator/regulator
- Repair the sensing wire or earth
- Replace a damaged battery
P0563 — frequently asked questions
Is it urgent? +
Yes. Sustained overvoltage destroys the battery and can take out ECUs and infotainment modules.
Can a jump-start cause it? +
No, but a deeply discharged battery makes a smart regulator push hard — test the battery before replacing the alternator.
Confirm the diagnosis before you buy parts
Send us the code, freeze-frame data and the vehicle — our engineers will tell you what to test first.