C05A2Brake Pressure Sensor E Range/Performance
- Generic OBD-II code · Chassis
- Can trigger limp mode
- Needs a drive cycle to confirm a fix
- How the car detects it
- Here sensor E delivers a voltage that is electrically valid but does not fit the braking situation: a drifting zero point, wrong gain or a value that disagrees with other pressure signals. No maker documents C05A2 publicly. The usual tests are known from related sensors. GM's hybrid brake controller learns each wheel sensor's zero while the pedal is released and flags an offset beyond ±1,500 kPa at once. A Bosch patent sets an offset fault when the compensation passes a limit, lights the ABS and ESC lamps and clears it only after a good check while driving. A Lucas/ZF patent opens the valves at standstill so all sensors see one pressure; with at least three of them the drifting one and its error can be identified. Trapped pressure, sensor drift or a ground offset are typical causes.
- What you may notice
- ABS and ESC warning lamps on
- Stability or regenerative brake functions reduced
- Likely causes
- LikelySensor zero point or gain drifted with age or temperature
- PossibleResidual pressure trapped in the circuit during the zero learn
- RareGround offset between sensor and module distorting the reading
- Repair
- Hard · Usually a job for a workshop.Typical cost: €80 – €1,800
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.