P2C03Fuel Pressure Regulator D Control Circuit Low
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P2C03 is set when the switched low side of the regulator D control circuit has contact with ground. GM documents it in 23OBDG07 and 24OBDG07 for the second fuel quantity control valve, where it mirrors P0091 of the first valve. With the driver off, a healthy circuit shows a voltage on this line; if it is pulled low, the ECM concludes that less than about 0.5 ohm separates the pin from ground. The check needs more than 10.9 V supply and an engine speed above 80 rpm and counts 20 events before reporting, on the first trip. A short at the supply end of the same driver is a different GM code (P3138), so the code already tells which wire to inspect: typically the low-side lead chafed against the engine or a damaged valve connector.
- What you may notice
- Check engine light on
- Reduced engine power
- Rough running at high load
- Likely causes
- LikelyLow-side wire chafed through to ground
- PossibleDamaged or wet valve connector
- RareInternal short in the quantity control valve
- 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 – €900
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.