OBD codes / P0563
P0563
SeriousSystem Voltage High
Treat P0563 with some urgency. Overcharging can cook the battery and stress electronics, and a battery damaged this way can fail suddenly. Get the charging system tested soon, and watch for a hot battery or a sulfur smell — if you notice those, have it looked at right away.
What this code means
P0563 means the car's electrical system voltage is running too HIGH — the charging system is overcharging. The usual cause is a faulty voltage regulator (built into the alternator on most modern cars), so the fix is often an alternator. A wiring or ground fault can also cause it. Overcharging matters because it can boil and ruin the battery and, in bad cases, damage sensitive electronics, so it shouldn't be left unaddressed.
Symptoms you might notice
- Battery or charging warning light
- Headlights or dash lights unusually bright
- A hot, swollen, or sulfur-smelling battery in bad cases
- Erratic electrical behavior
- Check-engine light
What it costs to fix
Typical range: $50–$700 · about ~0.3–2.5 hrs of labor
| If the cause is… | Part | Labor |
|---|---|---|
| Voltage regulator (where separate) | $30–$150 | ~0.3–1 hrs |
| Alternator (regulator built in) | $150–$600 | ~0.5–2.5 hrs |
| Wiring / ground repair | $10–$100 | ~0.3–1 hrs |
On most modern cars the regulator is part of the alternator, so the repair is an alternator — the main cost, with labor varying by access. Where the regulator is separate, or the cause is wiring/ground, it's cheaper. Check connections before condemning the alternator.
The price swings on which cause it turns out to be — so confirm the cause before paying. Diagnose P0563 for my exact vehicle →
How to fix P0563
Moderate — doable at home with common tools and patience
- Confirm the overcharge with a multimeter
With the engine running, measure voltage at the battery across idle and higher RPM. Readings holding above roughly 15 volts confirm the system really is overcharging — and this is worth confirming quickly, because sustained overvoltage cooks the battery and can damage electronics.
- Check the alternator's grounds and sense connections
Inspect and clean the alternator's ground path and, on cars that have one, the voltage-sense wire and its connector. A regulator that reads voltage through a bad connection thinks the system is low and cranks the output up — a wiring fix instead of an alternator.
- Watch regulator behavior under load
With the meter still connected, add electrical loads and vary RPM. A healthy regulator holds voltage steady; output that climbs unchecked with RPM regardless of load means the regulator has lost control.
- Replace the alternator
On most modern cars the regulator is built into the alternator, so a failed regulator means an alternator. Where the regulator is a separate serviceable part (some older or European designs), replace just the regulator.
- Verify the battery survived
After the repair, confirm charging voltage sits in the normal high-13s to mid-14s, then test the battery. Overcharging boils electrolyte and shortens battery life, so a battery that lived through a bad regulator may be quietly damaged.
DIY or shop? Diagnosis is simple multimeter work anyone can do in the driveway, and confirming the overcharge takes five minutes. The repair is where it splits: an accessible alternator is a satisfying DIY swap, while one buried under the intake or accessed from below turns into a shop job on labor alone. Either way, treat this code with some urgency — unlike a slow-charging system, an overcharging one actively damages the battery and risks the car's electronics while you wait.
Tools for the DIY steps: Digital multimeter · Socket set and wrenches · Belt tensioner tool (for alternator R&R) · Wire brush and contact cleaner · Memory saver (to preserve settings during battery disconnect)
Not sure which step applies to your car? Get the likely cause for your exact vehicle before buying anything for P0563.
Frequently asked
Can I drive with P0563?
Cautiously and not for long. Overcharging can damage the battery and electronics. Get the charging system tested soon, and if the battery smells like sulfur or feels hot, stop driving and have it checked.
What causes P0563?
Most often a faulty voltage regulator, which on modern cars lives inside the alternator — so the repair is usually an alternator. Wiring or ground faults that confuse the regulator can also cause it and are cheaper to fix.
Can overcharging hurt my car?
Yes — sustained high voltage can boil the battery dry and damage sensitive electronic modules. That's why P0563 is worth addressing promptly rather than ignoring the battery light.
How much does it cost to fix P0563?
If it's wiring or a separate regulator, modest. On most cars it means an alternator, which is the expensive end (labor varies by how accessible it is). Test the system before replacing parts.
Seeing P0563 on your car? Get a diagnosis specific to your exact year, make and model.
Diagnose P0563 for my vehicleSymptoms that trigger P0563
Drivers who get this code often notice one of these — each has its own likely-causes and cost guide:
Related trouble codes
Don’t have a scanner yet? A ~$25 Bluetooth adapter reads codes like P0563 from your phone — see our honest guide to the best OBD2 Bluetooth adapters.
Generic OBD-II reference. Manufacturer-specific behavior varies — confirm with a scan tool and, for safety-related codes, a professional inspection.