Chassis, generic

C05C5 Brake Pressure Sensor F Circuit Range/Performance

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modePossible

Pressure sensor F delivers a voltage inside the electrical window, yet the value does not fit the braking situation: wrong offset at rest, a reading that disagrees with deceleration or the brake switch, or a pressure that does not match pedal travel. No manufacturer documents C05C5 for sensor F. GM shows the method on other channels: the XT4 brake module flags pressure sensor A when its offset exceeds 12 bar with the pedal released, and Saab/GM treats a pressure signal that conflicts with vehicle deceleration as not plausible. Bosch compares measured pressure against a stored curve over input rod stroke. Unlike C05C6 and C05C7, the wiring is usually intact; suspect the sensor, its calibration or the hydraulics.

Likely causes

Pressure sensor F drifting or with offset out of tolerance
Calibration not matching after component replacement
Air in the system or hydraulic fault falsifying pressure
Increased contact resistance at the sensor connector

Symptoms

  • ABS/ESC warning lamp, stability control off
  • Unusual pedal feel or uneven braking assistance

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€80–1,500
Time0.5–3 h

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

Parts involved

brake pressure sensor f

Related codes

C05C4C05C6C05C7C053D

References: saabwisonline.com, gsi.ext.gm.com, patents.google.com.