Chassis
generic / SAE
C0091
Hydraulic Brake Pressure Sensor Circuit Range/Performance
The brake pressure sensor signal is outside the plausibility band relative to pedal application. Wiring faults of this kind typically come from chafing, water ingress at connector seals, or pin push-back — a wiggle test on the harness while the code is active often confirms the location.
SystemChassis
Typegeneric / SAE
GroupC0
Range / number– / 91
Possible causes
- Sensor drift with age high
- Internal hydraulic block leak low
- Sensor element aged beyond calibration window low
Symptoms
- ABS warning light on
- ESC/stability control deactivated
- Possible reduced brake assist
- Speedometer may behave erratically
Inspection / repair
- Difficulty: hard
- DIY: shop recommended
- Estimated cost: 200–1100 €
- Estimated time: 1–4 h
- Component: brake pressure sensor
- Component: abs control module
Sources
References
sae:J2012