Chassis, generic

C0273 Brake Booster Pressure Sensor Circuit Malfunction

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modePossible

Neither the reachable J2012 lists nor any maker describe C0273 as a booster pressure sensor code. GM's PIP5094 does include the number, and AA1Car translates it, like C0271 and C0272, as EBCM Malfunction, meaning an internal fault of the brake module. In that case the module is normally replaced after supply, ground and connector have been checked. The sensor in the title measures the vacuum or pressure stored in the brake booster. GM's patent US7467544 compares it with manifold vacuum at closed throttle and flags a reading drifted high or low, and can even correct a moderate drift. Electrical faults of that sensor are usually stored under the powertrain codes P0556 to P0559.

Likely causes

On GM vehicles internal fault of the brake control module
Low supply voltage, poor ground or corroded module connector
Faulty booster pressure sensor or its wiring

Symptoms

  • ABS and traction warning lamps on
  • ABS and stability functions disabled

Repair estimate

DifficultyHardWorkshop job
Parts and labour€50–1,500
Time0.5–3 h

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

Parts involved

abs control modulebooster pressure sensorbrake booster

Related codes

C0258C0279P0556C0266

References: static.nhtsa.gov, aa1car.com, patents.google.com.