P2500high severityPowertrain
Generator Lamp/L Terminal Circuit Low
on 2004 Audi S6 4.2L V8 · AWD
What this code means
Low signal on the alternator lamp/exciter circuit, preventing proper charging regulation.
Symptoms
- Battery light on
- Low charging voltage
- Check engine light
Common causes
- Broken exciter wire
- Failed voltage regulator
- Corroded alternator connector
- Blown dash bulb
Diagnostic steps
- Check charging system voltage
- Inspect alternator connector
- Measure exciter circuit voltage
Repair notes
Repair exciter circuit wiring or replace alternator.
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