P0003Powertrain
Powertrain · SAE
Fuel Volume Regulator Control Circuit Low
Meaning
The command signal to the fuel volume control valve is below the minimum expected limit. The ECM detects a control voltage that is too low, indicating a short to ground or partial open.
Common causes
- Short to ground in the FCV command wiring
- Corroded FCV connector with high resistance
- FCV valve with partially shorted winding
- ECM output driver failure
- Electrical interference in the control circuit
Symptoms
- Check-engine light on
- Rail pressure too low or unregulated
- Hard start, especially when cold
- Black smoke and power loss
- Limp-home mode active
Severity
High: insufficient rail pressure impairs combustion and can damage the pump; repair immediately.
What to do
- Measure voltage at the FCV command pin with ignition on
- Check for shorts to ground in the wiring between ECM and valve
- Inspect the FCV connector for corrosion or deformed terminals
- Measure FCV coil resistance
- Replace the valve or repair the wiring based on findings