C064BBrake Pressure Sensor M Circuit Low
- Generic OBD-II code · Chassis
- Can trigger limp mode
- How the car detects it
- Sensor M sits below its lower signal limit. Because modules often supply several pressure sensors together, a single low code can be the visible part of a wider fault: WABCO's trailer modulator powers all active sensors jointly, so a short on one sensor supply can pull others down too, and codes for neighbouring letters may then appear at the same time. In an ESP block, Bosch describes each sensor with four contacts, two for supply and two for the analog pressure signal, which makes a shorted or contaminated spring contact a plausible cause. GM's 2019 brake module flags its secondary circuit pressure sensor low under 4.61 % of supply for 100 ms; no maker publishes C064B itself. Check the shared supply before replacing sensor M.
- What you may notice
- Warning lamp on, possibly with further pressure sensor codes
- Electronic brake functions reduced to a fallback mode
- Likely causes
- LikelyShared sensor supply shorted, pulling several sensors low
- PossibleSignal line or contact of sensor M shorted to ground
- RareSensor element failed
- Repair
- Medium · Usually a job for a workshop.Typical cost: €50 – €1,600
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.