What it means
Same as P057C on sensor B. 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.
At a glance
- Usually lights the check-engine light
How it works
Brake pedal position sensor B reports pedal travel to the control module, which monitors its signal circuit. This code sets when the sensor B signal is lower than expected, often because the signal wire is shorted to ground.
Common causes
Most likely first.
- Signal shorted to ground
- Connector pins corroded - high contact resistance
- Harness chafing through insulation
Symptoms
- Brake or check-engine warning light may illuminate
- Stop-start or other brake-related functions may be unavailable
How to diagnose it
- Review freeze-frame data and graph live readings for brake pedal sensor B while comparing them with sensor A through pedal travel.
- Inspect sensor B's connector and harness for chafing, moisture, corrosion, or a pin pushed back into the connector.
- With live data displayed, gently move the sensor B harness to see whether the low reading or fault status changes.
- Use the vehicle wiring diagram to check the sensor B signal wire for a short to ground and inspect terminals for poor contact.
- If the wiring and connector are sound, test sensor B and its control-module circuit using the manufacturer's procedure.
Common fixes
- Repair signal-wire insulation damaged by chafing or contact with ground.
- Clean or replace corroded sensor B connector terminals and seals.
- Reseat or repair a pushed-back pin in the sensor B connector.
- Replace sensor B if it continues to produce a low signal with sound wiring.
Can I keep driving?
Brake-related functions such as stop-start may be unavailable, even if ordinary braking still feels normal. If a brake warning appears or pedal behavior changes, stop safely and have the fault checked before driving further.
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.