P0563 Code: System Voltage High — Causes & Fix
P0563 means the ECM has detected a higher-than-normal system (battery) voltage — usually a charging-system problem.
- Applies to
- All OBD-II vehicles (any make or model)
- Est. repair cost
- $40 – $500
- Time to fix
- 30 minutes – 2 hours
What it means
Causes include an overcharging alternator/voltage regulator or a wiring/ground fault. P0563 is a generic OBD-II powertrain code defined in the SAE J2012 standard, so it applies to virtually any 1996-or-newer petrol car or light truck regardless of make. Fix the underlying fault, then clear the code with an OBD-II scan tool — it will return if the problem isn't resolved.
Symptoms
- Check engine light on
- Bright or flickering lights
- Possible electrical component stress
How to fix it
- 1
Test charging voltage
1. Measure battery voltage with the engine running — it should be within the charging spec (~13.5–14.7V). 2. Replace an overcharging alternator/regulator.
- 2
Check grounds
1. Inspect battery and engine grounds. 2. Repair, then clear the code.
Frequently asked questions
What causes high system voltage?
Most often a faulty voltage regulator/alternator overcharging the system. Confirm with a voltmeter across the battery.
Last updated July 19, 2026
Guidance only — always consult a qualified professional or the official service manual before carrying out repairs.