C0046Brake Pressure Sensor A/B
- Generic OBD-II code · Chassis
- Can trigger limp mode
- How the car detects it
- A correlation code for the pair of brake pressure sensors A and B, set when their readings do not agree within the expected tolerance. Where C0044 and C0045 flag a single-sensor electrical fault, this code is a plausibility fault: at the same instant both sensors should report consistent pressure (allowing for their known relationship), and a persistent mismatch indicates one sensor has drifted, a hydraulic fault separates the circuits, or a signal is corrupted. The stability and brake modules rely on agreement to trust the pressure reading for stability, brake assist and brake-by-wire control. A fault disables those functions and sets the ABS or brake warning lamp while base braking remains. NHTSA lists C0046 in the J2012 table of its EPS report. No manufacturer documents it publicly.
- What you may notice
- ABS or brake warning lamp on
- Stability and assist functions disabled
- Changed brake assist behaviour
- Likely causes
- LikelyOne pressure sensor drifted or biased
- PossibleHydraulic fault separating the circuits
- RareSignal corruption or wiring fault
- Repair
- Workshop only · Usually a job for a workshop.Typical cost: €400 – €2,200
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.