What it means
The control module detects a fault 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 determine pedal position for functions such as cruise cancellation and, on some vehicles, brake-light control. P057A sets when the electrical circuit for sensor A has a general fault, such as an open connection, rather than a specifically identified low or high signal.
Common causes
Most likely first.
- Open in sensor or wiring
- Pin pushed back out of connector body
- Cracked solder joint inside the module or sensor
Symptoms
- Check-engine light may come on
- Cruise control may not engage or may disengage unexpectedly
- Brake lights may behave erratically
- Brake pedal or braking response may seem inconsistent if the signal is used by related systems
How to diagnose it
- Record freeze-frame data and observe Brake Pedal Position Sensor A on a scan tool while slowly pressing and releasing the brake pedal.
- Check whether brake lights operate consistently and inspect the sensor A connector for loose terminals or pins pushed back into the housing.
- Inspect the sensor A wiring for an open, damaged insulation, or poor connection between the sensor and module.
- With the wiring diagram, test circuit continuity and connector pin fit, then check sensor output through the pedal's travel.
- Compare sensor and module readings with the manufacturer's specification before identifying an internal sensor or module fault.
Common fixes
- Reseat the sensor A connector and repair loose or pushed-back terminals.
- Repair an open or damaged section of the sensor A wiring.
- Replace a failed Brake Pedal Position Sensor A.
- Repair a confirmed internal sensor or module connection fault.
Can I keep driving?
Because this signal may affect brake lights and cruise cancellation, check that the brake lights work before driving and do not use cruise control. If brake lights are unreliable or pedal response seems abnormal, avoid driving and have the fault assessed promptly.
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.