What it means
The control module detects a high signal in the Brake Pedal Position Sensor A circuit.
At a glance
- Usually lights the check-engine light
How it works
The control module monitors Brake Pedal Position Sensor A to track pedal movement. P057D sets when the sensor signal is higher than the expected range, which can occur when the signal wire contacts a supply voltage or the circuit has a connection fault.
Common causes
Most likely first.
- Signal shorted to supply
- Connector pins corroded - high contact resistance
- Supply wire pinched against B+ source
Symptoms
- Check-engine light may come on
- Cruise control may not engage or may disengage unexpectedly
- Brake lights may behave erratically
- Brake pedal position display or related system response may be inconsistent
How to diagnose it
- Record freeze-frame data and monitor the sensor A signal while slowly pressing and releasing the brake pedal to confirm the high reading.
- Check brake-light operation and inspect the sensor A connector for corrosion, loose pins, or pin push-back.
- Inspect the signal harness for pinched insulation or contact with a powered wire.
- Use the wiring diagram to test the sensor A circuit for a short to supply and verify connector terminal condition.
- Compare sensor output and module input with the manufacturer's specification to distinguish a sensor fault from a wiring or module fault.
Common fixes
- Repair wiring pinched against a supply source or shorted to a powered circuit.
- Clean or replace damaged sensor A connector terminals.
- Replace Brake Pedal Position Sensor A if its output remains high with correct wiring.
- Repair or replace the module only if it misreads a verified sensor signal.
Can I keep driving?
A high pedal-position signal may disrupt cruise cancellation and can coincide with erratic brake-light behavior. Check the brake lights before driving, avoid cruise control, and stop if braking or pedal response seems abnormal.
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.