What it means
The control module monitors brake pedal position sensor B and checks whether its signal changes as expected across pedal travel. It sets this code when the signal is present but falls outside the expected range or response.
At a glance
- Usually lights the check-engine light
How it works
Brake pedal position sensor B sends a signal that changes as the pedal moves, and the control module checks whether that change follows the expected range and pattern. This code sets when the signal is present but its level or response is implausible across pedal travel.
Common causes
Most likely first.
- Worn sensor track or internal sensor fault
- Misadjusted or damaged sensor
- Loose, corroded, or damaged wiring or connector
Symptoms
- Brake or check-engine warning light may illuminate
- Stop-start or other brake-related functions may be unavailable
How to diagnose it
- Check freeze-frame data and graph live readings from sensors A and B while slowly pressing and releasing the brake pedal.
- Inspect sensor B, its mounting, connector, and wiring for looseness, damage, corrosion, or signs the sensor has shifted.
- Check whether sensor B's signal changes smoothly through pedal travel and compare its behavior with sensor A using the manufacturer's specifications.
- Inspect the sensor B circuit for intermittent contact, poor terminal fit, or wiring damage that could distort its reading.
- If the circuit and mounting are sound, test sensor B for an internal fault and verify its adjustment using the manufacturer's procedure.
Common fixes
- Secure a loose sensor B connector or repair damaged wiring.
- Correct sensor mounting or adjustment if it has shifted.
- Clean or replace corroded or loose connector terminals.
- Replace sensor B if its signal remains out of range or erratic after circuit checks.
Can I keep driving?
Brake-related assistance or stop-start may be limited while the fault is present. If the brake warning is on or pedal feel or braking behavior changes, stop safely and arrange prompt inspection; do not rely on electronic assistance.
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.