What it means
The control module monitors system voltage and sets this code when voltage rises above its calibrated threshold. The code indicates excessive system voltage but does not identify the cause.
At a glance
- Usually lights the check-engine light
How it works
The alternator and its voltage regulator supply electrical power and recharge the battery while the engine runs. The control module monitors system voltage, and P0563 sets when voltage rises above its calibrated limit, indicating possible overcharging.
Common causes
Most likely first.
- Voltage regulator failed
- Alternator overcharging
Symptoms
- Check-engine or battery warning light may come on
- Lights may appear unusually bright
- Electrical accessories may behave erratically
- Battery may become unusually hot or emit an odor
How to diagnose it
- Review freeze-frame data and related charging codes to see whether the high-voltage condition occurred with the engine running or under particular electrical loads.
- Inspect the battery for heat, swelling, leaks, or odor, and check the alternator wiring and grounds for loose or damaged connections.
- Measure system voltage at the battery with the engine running and compare it with the manufacturer's specification; stop testing if the battery is overheating or venting.
- Check alternator output under the manufacturer's specified test conditions to confirm whether charging voltage remains excessive.
- If alternator output is abnormal, test the regulator and its sense and ground circuits before deciding which component has failed.
Common fixes
- Repair loose or corroded alternator sense, power, or ground connections.
- Repair damaged charging-system wiring.
- Replace a failed voltage regulator if it is serviceable separately.
- Replace or repair the alternator if its regulator or output is causing overcharging.
Can I keep driving?
Do not continue driving if the battery is unusually hot, swollen, leaking, or giving off an odor; overcharging can damage the battery and vehicle electronics. If there are no warning signs, limit driving and have the charging system checked promptly.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.