C0240
Brake Pressure Sensor
The ABS or stability control module has detected a fault in a brake pressure sensor. Pressure information is used by ESP and brake assist to determine driver intent and modulation pressure during regulation.
- Check engine light: Not always
- Emissions related: No
- Repair difficulty: medium
Symptoms
- ABS warning light on
- ESC/stability control deactivated
- Possible reduced brake assist
- Speedometer may behave erratically
Common causes
Ordered by how often each turns out to be the cause.
- Brake pressure sensor failedCommon
- Wiring or connector faultPossible
- Air in brake systemLess likely
Parts involved
- Brake Pressure Sensor
- ABS Hydraulic Unit
- ABS Control Module
C0240 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.