Chassis, generic

C0303 Inlet Valve Front Right Performance

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modePossible

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.

Likely causes

Inlet valve stuck from debris after brake work
Open or shorted valve coil inside the hydraulic unit
Low supply voltage to the valve circuit during self-test

Symptoms

  • ABS, traction and stability control lamps on
  • Car pulls to the left when braking

Repair estimate

DifficultyHardWorkshop job
Parts and labour€150–1,500
Time1–3 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

rf abs inlet valveabs hydraulic blockabs control module

Related codes

C0304C0300C0307

References: saabwisonline.com, saabwisonline.com, bosch-mobility.com.