System Voltage High
The P0563 code means the vehicle's onboard diagnostic system has detected: System Voltage High. This is a moderate severity code.
- Keep driving?
- Short distances only
- DIY difficulty
- moderate
- Estimated cost
- $150 - $550 (parts and labor)
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Common Symptoms
- Bulbs burning out frequently
- Battery overheating or bulging
- Electrical components failing prematurely
- Strong sulfur or rotten egg smell from battery
- Check engine light on
Probable Causes (Ranked by Likelihood)
- Faulty voltage regulator (overcharging) Very High
- Failing alternator with internal regulator issue High
- Poor ground connection to alternator or PCM Moderate
- Incorrect alternator installed (wrong output spec) Moderate
- PCM voltage sensing circuit error Low
Step-by-Step Diagnostic Procedure
-
Measure charging voltage with engine running -- should be 13.5-14.5V; over 15V indicates overcharging
-
Test voltage at different RPMs -- should remain under 14.8V even at 3000 RPM
-
Check alternator ground connection for corrosion or looseness
-
Inspect battery for signs of overcharging -- swollen case, excessive bubbling, or electrolyte loss
-
If voltage is over 15V, replace alternator or external voltage regulator as applicable
Common Fixes by Vehicle
What techs usually find when diagnosing P0563 on specific vehicles — tap your vehicle for the fix and the exact part:
2007-2018 GMC Sierra/Chevrolet Silverado 5.3L Moderate DIY
System voltage too high (above 16V) indicates a failed voltage regulator inside the alternator overcharging the battery. This can boil the battery and damage electronics. Replace the alternator immediately. Check the battery for swelling or boiling electrolyte as signs of overcharge damage.
Labor: 1-1.5 hours2008-2019 Ford Escape 2.5L/2.0L Moderate DIY
The PCM-controlled alternator on Ford Escape uses a smart charging system. A faulty PCM signal wire to the alternator can cause overcharging. Check the single-wire signal connector at the alternator for corrosion. If the alternator is genuinely overcharging, replace it with a Motorcraft unit.
Labor: 1-1.5 hours2009-2018 Dodge Journey 3.6L Moderate DIY
High system voltage on the Dodge Journey is caused by a failed voltage regulator in the generator. The 3.6L Pentastar uses a PCM-controlled charging system -- verify the PCM is commanding normal charging voltage before replacing the alternator. Update the PCM software if a TSB applies to your build date.
Labor: 1.5-2 hoursFrequently Asked Questions
Can I drive with code P0563?
Only for short distances to a repair shop. High system voltage (overcharging) can damage the battery, blow light bulbs, and fry sensitive electronic components including the PCM, radio, and instrument cluster. The longer you drive, the more damage can occur.
What voltage is too high for a car?
Normal charging voltage is 13.5-14.5V. Anything consistently above 15V is considered overcharging and is harmful. At 16V or higher, battery damage, bulb failures, and electronic component damage occur rapidly.
Can overcharging damage my battery?
Yes. Overcharging causes the battery electrolyte to boil, which can warp the battery case, corrode the terminals, release hydrogen gas (explosive), and permanently damage the battery plates. A swollen battery case is a clear sign of overcharging.
Sources
This page is built from documented references. Verify against your own service info before repair work.
P0563 on Diesel, EV & Equipment
The same code ID appears across other engines and platforms. The diagnostic flow varies by manufacturer — these are the platform-specific breakdowns:
See All Codes & Fixes for Your Vehicle
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