Chassis, generic

C0258 Brake Booster Vacuum Sensor Circuit

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

No public record of C0258 exists: the publicly available J2012 lists, the NHTSA bulletin index and the GM and Saab indexes all lack it. Only the sensor named in the title can be described. A booster vacuum sensor tells the control unit whether enough vacuum is stored for power-assisted braking; GM needs it on cylinder-deactivation engines, which return to all cylinders when vacuum gets low. GM patent US7076347 checks the sensor with the throttle almost closed: over one second the gap to manifold vacuum must shrink to near zero. GM patent US7467544 also catches a reading biased high or low. Electrical faults of such a sensor are normally stored as powertrain codes P0556 to P0559 rather than as a chassis code.

Likely causes

Open or shorted sensor supply, ground or signal wire
Faulty or drifting vacuum sensor
Leaking vacuum hose, check valve or booster diaphragm

Symptoms

  • Warning lamp or message about brake assistance
  • Cylinder deactivation or engine stop-start inhibited on affected vehicles

Repair estimate

DifficultyMediumDIY possible
Parts and labour€30–300
Time0.3–1.5 h

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

Parts involved

brake booster vacuum sensorvacuum hose

Related codes

P0556P0557P0558C0269C0273

References: patents.google.com, patents.google.com.