Chassis, generic

C05C7 Brake Pressure Sensor F Circuit High

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modePossible

Here the voltage of pressure sensor F rises above the top of its measuring range. With the common pull-down input, Denso explains that a lost sensor ground lifts the output past 4.7 V, which lies in the upper fault band; a short of the signal to a voltage source has the same effect. Industrial sensors such as the Honeywell MIP series deliberately park their output near 97.5 % of supply to signal an internal fault or overpressure. Saab/GM detects a short to voltage on the brake pressure signal or reference within 0.1 s. No carmaker documents C05C7 for sensor F. Check the ground wire first, then insulation of the signal line. C05C6 is the low counterpart, C05C5 the in-range plausibility fault.

Likely causes

Open or high-resistance sensor ground
Signal wire shorted to a voltage source
Sensor F reporting an internal fault at the upper rail

Symptoms

  • ABS/ESC lamp on, stability functions switched off
  • Live data shows implausibly high brake pressure with pedal released

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€50–1,200
Time0.5–2.5 h

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

Parts involved

brake pressure sensor fsensor wiring

Related codes

C05C6C05C8C05C9C05A0

References: patents.google.com, prod-edam.honeywell.com, saabwisonline.com.