Chassis, generic

C0302 Outlet Valve Front Left Performance

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modePossible

C0302 has no public footprint: the publicly available J2012 tables, GM's PIP5094, the AA1Car chart and the NHTSA bulletin index all lack it. This text therefore covers only the front left outlet valve named in the title. Unlike the inlet valve it stays closed at rest and opens only when the brake module wants to drop pressure at a locking wheel; the released fluid goes into an accumulator from which the return pump feeds it back. TRW calls this part the dump valve. If it opens too slowly, the front left wheel can lock; if it leaks, pressure escapes and the pedal sinks or the car pulls right. Bosch places these valves, the return pump and the control unit together in one hydraulic unit, so a valve fault usually means repairing that unit.

Likely causes

Outlet valve seat leaking because of dirt or wear
Valve coil or its driver in the brake module faulty
Old or wrong brake fluid slowing the valve

Symptoms

  • ABS warning lamp on, ABS switched off
  • Front left wheel locks or pedal sinks slowly

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

lf abs outlet valveabs hydraulic blockabs control module

Related codes

C0300C0304C0309

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