System Voltage High
The DURAMAX-P0563 (Duramax) diesel fault code means: System Voltage High. This is a moderate severity code.
- Keep driving?
- Yes, with caution
- DIY difficulty
- intermediate
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What Are the Symptoms of DURAMAX-P0563?
- Check Engine Light on
- Possible flickering lights or warnings
- Battery may smell or boil
What Causes DURAMAX-P0563? (Most Likely First)
- Charging system overcharging (regulator or alternator fault) High
- Jump-start or charger connected at the wrong voltage Moderate
- Poor ground giving a false reading Low
Can I Still Drive with DURAMAX-P0563?
Yes, with caution. DURAMAX-P0563 is rated moderate severity. Keep trips short and get it diagnosed soon rather than waiting for symptoms to worsen.
Frequently Asked Questions
What does P0563 mean on a Duramax?
P0563 means System Voltage High. The engine computer is seeing a supply voltage above its normal range.
Is P0563 a Duramax-specific code?
No. P0563 is a generic OBD-II code defined by SAE J2012, so it means the same thing on any vehicle that sets it. The exact conditions GM uses to set it on its diesels are in GM service information.
Mechanics Guide Step-by-step diagnosis
How Do You Diagnose DURAMAX-P0563?
Test the batteries and the charging voltage with a meter.
Clean and tighten the battery and ground connections.
Compare the voltage the engine computer reports with the voltage at the battery.
Sources 1
This page is built from documented references. Verify against your own service info before repair work.
- SAE J2012Diagnostic Trouble Code Definitions (defines P0563 as a generic OBD-II code)
P0563 on Other Platforms
The same code ID appears across other engines, vehicles, and equipment. Diagnostic flow varies by platform — see the matching breakdown:
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