P2504critical severityPowertrain
Charging System Voltage High
on 2000 Audi A4 2.8L V6 · AWD
What this code means
Charging system output voltage exceeds maximum safe threshold.
Symptoms
- Battery boiling/swelling
- Bulbs burning out frequently
- Check engine light
- Electrical component damage
Common causes
- Failed voltage regulator
- ECM charging control fault
- Ground strap issue
Diagnostic steps
- Measure charging voltage at various RPM
- Check voltage regulator
- Inspect ground straps
Repair notes
Replace alternator or voltage regulator. Check and repair grounds. Overcharging can damage expensive electronics.
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