P2503high severityPowertrain
Charging System Voltage Low
on 2009 Audi R8 5.2L V10 (Gen 1, 525hp) · AWD
What this code means
Charging system output voltage is below minimum threshold.
Symptoms
- Battery light on
- Dimming lights
- Slow cranking
- Accessories failing
Common causes
- Worn alternator
- Slipping belt
- High resistance connection
- Battery drawing excessive current
Diagnostic steps
- Measure voltage at battery and alternator
- Check belt
- Load test battery
- Check cable connections
Repair notes
Replace alternator. Inspect belt and cable connections.
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