P2C03 code meaning
Fuel Pressure Regulator D Control Circuit Low
Powertrain system Generic code P2Cxx codes Check engine light
What P2C03 means
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.
P2C03 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium
- Typical labor0.5 to 3 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P2C03
- Check engine light on
- Reduced engine power
- Rough running at high load
Common causes of P2C03
- Most likelyLow-side wire chafed through to ground
- PossibleDamaged or wet valve connector
- Less likelyInternal short in the quantity control valve
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Fuel pressure regulator dHigh pressure fuel pumpWiring harness
What each part of P2C03 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| C | Area: hybrid propulsion. |
| 03 | The exact fault in that area. |
What to do next
- Note P2C03 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P2C03
What does P2C03 mean?
P2C03 means "Fuel Pressure Regulator D Control Circuit Low". P2C03 is set when the switched low side of the regulator D control circuit has contact with ground. It is a generic code, so it means the same on every make.
Is it safe to drive with P2C03?
Drive gently and only to a workshop. With P2C03 the car can go into limp mode (reduced power) to protect itself.
Will P2C03 fail an emissions test?
Yes, it can. P2C03 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P2C03 to fix?
Difficulty: medium. A typical repair takes 0.5 to 3 hours of work. This is a job for a workshop.
Will P2C03 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.