C0291Brake Pedal Apply Sensor Circuit Malfunction
- Generic OBD-II code · Chassis
- Can trigger limp mode
- How the car detects it
- C0291 is in no publicly available J2012 table, and no maker uses it for a brake apply sensor. GM names the number in its PIP5094 keyword list, and AA1Car's table of GM brake codes reads it as Lost Communications With BCM, a lost data link to the body module. An apply sensor tells the control units whether, and how firmly, the pedal is pressed. GM handles that job with a pedal position sensor: on the 2011 Saab 9-4X it is read by the body module, which needs 9 to 16 V supply and stores separate subcodes for grounded or open lines, battery shorts, implausible jumps and a missing rest position learn. A failure there affects stop lamps, shift lock and the electric park brake release.
- What you may notice
- Stop lamps stay on or do not light
- Cruise control or shift lock release not working
- ABS or stability control warning lamp on
- Likely causes
- PossibleChafed wire or loose connector at the pedal sensor
- PossiblePedal sensor replaced or pedal adjusted without relearning the rest position
- RareData link to the body module interrupted (GM meaning of the number)
- Repair
- Medium · Often possible to do yourself.Typical cost: €30 – €300
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.