P0004

Symptoms

• Difficulty starting the engine
• Unstable idling
• Loss of engine power
• Black smoke from the exhaust pipe
• Increased fuel consumption
• Check Engine Light on Dashboard
• Engine transition to emergency mode

Causes

• Short circuit in the wiring of the fuel volume regulator
• Malfunction of the fuel volume regulator itself
• Damage to the regulator connector
• Oxidation or corrosion of contacts
• Engine control unit malfunction
• Ground wire break
• Moisture getting into electrical connections

How to Fix

1. Check battery voltage and alternator charging
2. Read error codes and record engine operating parameters
3. Check the condition of the fuel volume regulator connector
4. Measure the resistance of the regulator control circuit
5. Check the supply voltage on the regulator
6. Test the fuel volume regulator with a multimeter
7. Check the integrity of the wiring from the ECU to the regulator
8. If necessary, replace the fuel volume regulator
9. Clear error codes and test drive

Related codes

Error P0004 by Vehicle Brand