C0641Brake Pressure Sensor K Circuit/Open
- Generic OBD-II code · Chassis
- Can trigger limp mode
- How the car detects it
- Brake pressure sensor K has an open circuit. Because the letter I is skipped in this series, K stands for a tenth pressure sensor, which is rare in cars; no carmaker publishes C0641 and the assignment is unknown. Heavy vehicles show how many pressure inputs one brake ECU can have: Bendix's EC-80 ESP reads a brake demand sensor in each of the two air circuits plus a load sensor and keeps a separate open-or-shorted code for each; ESP is then switched off while ABS and traction control stay active. In passenger cars the sensor often plugs straight into the module, as in a Kelsey-Hayes design, which removes harness opens but not contact faults. Honeywell notes that the resulting level after an open depends on whether the input has a pull-up or a pull-down resistor.
- What you may notice
- ESC or ABS warning lamp on
- Stability control off, basic ABS may remain available
- Likely causes
- LikelyPoor contact between sensor and module or harness connector
- PossibleOpen conductor where an external harness is used
- RareInternal open in sensor K
- Repair
- Medium · Usually a job for a workshop.Typical cost: €40 – €1,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.