Chassis, generic

C0544 Brake Pressure Sensor B Circuit/Open

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modePossible

The brake module sees a general electrical fault in the circuit of pressure sensor B, usually an interruption in signal, feed or ground. No maker publishes this exact meaning; note that GM bulletins use C0544 for a different, steering-related fault in its power steering module, so a GM scan result must be read with GM definitions. For the component itself, Saab 9-5 (2011) data shows how such circuits are watched: the brake module watches both the sensor feed and its output line, sets a fault after 0.1 s of open or high resistance and disables ABS, traction and stability control for that ignition cycle. Bentley shows that sensor B can sit inside the ESC unit, which then has to be replaced as a whole. C0541 covers implausible values, C0542 and C0543 low and high voltage.

Likely causes

Connector at sensor or brake module loose or corroded
Interrupted signal, feed or ground wire
Open inside the sensor or the ESC unit carrying it

Symptoms

  • ABS, traction and stability warning lamps on
  • Driver assistance relying on brake pressure unavailable

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€50–2,500
Time0.3–3 h

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

Parts involved

brake pressure sensor bsensor wiring

Related codes

C0541C0542C0543C0540

References: saabwisonline.com, saabwisonline.com, static.nhtsa.gov, static.nhtsa.gov.