P0004moderate severityPowertrain
Fuel Volume Regulator Control Circuit High
on 2025 Subaru Levorg 1.8L H4 Turbo CB18 · AWD
What this code 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
Repair notes
Repair open circuit or replace regulator.
Other Powertrain codes on this vehicle
P0001
Fuel Volume Regulator Control Circuit/Open
P0002
Fuel Volume Regulator Control Circuit Range/Performance
P0003
Fuel Volume Regulator Control Circuit Low
P0010
Intake Camshaft Position Actuator Circuit/Open Bank 1
P0011
Intake Camshaft Position Timing Over-Advanced Bank 1
P0012
Intake Camshaft Position Timing Over-Retarded Bank 1
P0013
Exhaust Camshaft Position Actuator Circuit/Open Bank 1
P0014
Exhaust Camshaft Position Timing Over-Advanced Bank 1
P0015
Exhaust Camshaft Position Timing Over-Retarded Bank 1
P0016
Crankshaft Position/Camshaft Position Correlation Bank 1 Sensor A