C0303 code meaning
Inlet Valve Front Right Performance
What C0303 means
C0303 has no public evidence at all: the accessible J2012 lists, GM's PIP5094 keyword list, AA1Car's GM table and the NHTSA index all lack it. The title points to the front right inlet valve. A performance fault here means the brake module saw the valve respond wrongly, for example a coil current out of range during the self-test or a wheel that does not hold pressure as commanded. In the Saab 9-5 ESP valve block twelve solenoid valves sit together, including an inlet/outlet pair for every wheel, and any valve fault switches ABS, traction and stability control off and lights their lamps. A front right inlet valve that stays shut leaves that wheel underbraked, so the car may pull to the left; one that will not close lets the wheel lock in ABS braking.
C0303 at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modePossible
- Repair difficultyHard
- Typical labor1 to 3 hours
- Clears after repairWhen cleared with a scanner
Symptoms of C0303
- ABS, traction and stability control lamps on
- Car pulls to the left when braking
Common causes of C0303
- PossibleInlet valve stuck from debris after brake work
- PossibleOpen or shorted valve coil inside the hydraulic unit
- Less likelyLow supply voltage to the valve circuit during self-test
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Rf ABS inlet valveABS hydraulic blockABS control module
What each part of C0303 means
| C | Chassis system: brakes, ABS, steering and suspension. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 03 | The exact fault in that area. |
What to do next
- Note C0303 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 C0303
What does C0303 mean?
C0303 means "Inlet Valve Front Right Performance". C0303 has no public evidence at all: the accessible J2012 lists, GM's PIP5094 keyword list, AA1Car's GM table and the NHTSA index all lack it. It is a generic code, so it means the same on every make.
Is it safe to drive with C0303?
Drive gently and only to a workshop. With C0303 the car can go into limp mode (reduced power) to protect itself.
Will C0303 fail an emissions test?
C0303 is not an emissions code, so on its own it usually does not fail an emissions test. Other stored codes or a lit check engine light still can.
How hard is C0303 to fix?
Difficulty: hard. A typical repair takes 1 to 3 hours of work. This is a job for a workshop.
Will C0303 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.