P2603moderate severityPowertrain
Coolant Pump A Control Circuit High
on 2004 Audi S4 4.2L V8 · AWD
What this code means
High voltage on auxiliary coolant pump circuit.
Symptoms
- Check engine light
- Pump runs constantly
Common causes
- Open ground
- Short to power
- Control module issue
Diagnostic steps
- Check ground circuit
- Measure voltage
Repair notes
Repair wiring or replace pump.
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