P00C9 code meaning
Fuel Pressure Regulator A Solenoid Supply Voltage Control Circuit Low
Powertrain system Generic code P00xx codes Check engine light
What P00C9 means
Some engine control modules switch the solenoid of fuel pressure regulator A on both sides: the ground side is monitored by P0090 to P0092, the supply side (high-side driver) by P00C8 to P00CA. On gasoline direct injection the regulator is typically the control valve on the high-pressure pump; on some diesels it is the regulator designated as regulator 1. P00C9 reports a short to ground on the supply side. Rail pressure can then not be controlled, causing starting problems, stalling or reduced power; documented systems turn on the warning light in the first drive cycle.
P00C9 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium, DIY possible
- Typical labor0.5 to 3 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P00C9
- Check engine light on
- Hard starting or stalling
- Loss of power or limp mode
Common causes of P00C9
- Most likelySupply wire to the solenoid chafed and shorted to ground
- PossibleSolenoid coil shorted
- PossibleWater or corrosion in the connector
- Less likelyHigh-side driver in the engine control module faulty
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Fuel pressure regulatorFuel pressure regulator wiringHigh pressure fuel pumpEngine control module
What each part of P00C9 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 0 | Area: fuel and air metering and auxiliary emission controls. |
| C9 | The exact fault in that area. |
What to do next
- Note P00C9 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 P00C9
What does P00C9 mean?
P00C9 means "Fuel Pressure Regulator A Solenoid Supply Voltage Control Circuit Low". Some engine control modules switch the solenoid of fuel pressure regulator A on both sides: the ground side is monitored by P0090 to P0092, the supply side (high-side driver) by P00C8 to P00CA. It is a generic code, so it means the same on every make.
Is it safe to drive with P00C9?
Drive gently and only to a workshop. With P00C9 the car can go into limp mode (reduced power) to protect itself.
Will P00C9 fail an emissions test?
Yes, it can. P00C9 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 P00C9 to fix?
Difficulty: medium. A typical repair takes 0.5 to 3 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P00C9 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.