What it means
This code identifies a fault associated with brake pressure sensor A or B. The specific failure depends on the diagnostic subtype.
How it works
Brake pressure sensors A and B report hydraulic pressure to the brake control module so it can manage ABS and stability functions. This subfault code points to a fault associated with one of those sensors; the diagnostic subtype is needed to identify which sensor or failure condition is involved.
Common causes
Most likely first.
- Faulty brake pressure sensor
- Damaged or corroded sensor connector
- Open or shorted wiring
- Poor sensor ground or reference voltage
Symptoms
- ABS warning light
- Brake system warning light
- Reduced or disabled ABS or stability control
- Changes in brake pedal feel
How to diagnose it
- Read the brake control module's subtype details and freeze-frame data to see whether sensor A or B is identified and when the fault occurred.
- Compare live readings from sensors A and B while applying the brake, and check whether either reading is missing, implausible, or fails to respond.
- Inspect the identified sensor, connector, and nearby wiring for corrosion, fluid contamination, loose pins, or damage.
- Check the sensor's reference supply, ground, and signal circuit for opens or shorts, using the vehicle wiring information and manufacturer's specification.
- If the wiring and supplies are sound, test the identified pressure sensor and brake control module inputs according to the manufacturer's procedure.
Common fixes
- Repair a loose, corroded, or damaged connector or wire at the affected pressure sensor.
- Restore a poor sensor ground or reference-voltage connection.
- Replace the faulty pressure sensor A or B identified by subtype and testing.
- Repair or replace the brake control module if its input circuit is confirmed faulty.
Can I keep driving?
The base code does not identify which pressure sensor failed, and ABS or stability assistance may be reduced or unavailable. Drive cautiously only if the brakes feel normal, avoid hard braking and slippery roads, and stop if pedal feel changes or a brake warning appears.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.