P2C04Fuel Pressure Regulator D Control Circuit High
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P2C04 covers the opposite electrical fault to P2C03: the switched ground end of the regulator D circuit is connected to battery voltage. In GM's 23OBDG07 and 24OBDG07 tables the circuit belongs to the second fuel quantity control valve, counterpart of P0092 on the first. The ECM detects it while the driver is switched on: the line should then be pulled down, and if the voltage stays high, the module assumes a short of less than 0.5 ohm to the injector supply. Enable conditions are supply above 10.9 V and engine speed above 80 rpm; 20 failed events set the code on the first trip. As long as the short exists the valve cannot be switched, so pump output for that circuit is lost. Look for insulation damage where the harness runs near hot or moving parts, and for moisture in the connector.
- What you may notice
- Check engine light on
- Reduced power, possibly limp mode
- Engine may hesitate under load
- Likely causes
- LikelyLow-side wire shorted to a supply voltage
- PossibleMoisture or corrosion bridging pins in the valve connector
- RareFaulty output stage in the engine control module
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €60 – €1,200
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.