P0004
PowertrainFuel Air Meteringmoderate severityFuel Volume Regulator Control Circuit High
What P0004 Means
The PCM detected a higher than expected signal from the fuel volume regulator control circuit.
Symptoms
- Check Engine Light
- High fuel pressure
- Rich running
- Black exhaust smoke
Common Causes
- Open in regulator ground circuit
- Faulty regulator
- PCM driver failure
- Wiring issue
Diagnostic Steps
- Check circuit voltage
- Test regulator resistance
- Inspect ground connection
- Check PCM output
Where to start: Repair open circuit or replace regulator.
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