P057A: Brake Pedal Position Sensor A Circuit/Open

The brake pedal position sensor is an analogue 5 V sensor, usually Hall-type, giving the pedal position continuously instead of a switch – for brake lights, cruise control, stop-start, brake-throttle override and regenerative braking. GM (from about 2012) and Stellantis read it in the engine module, Saab's 9-4X and 9-5 in the body module; its learned rest position (about 1 V) must be relearned after replacement. P057A is the general circuit or open-circuit fault. No manufacturer document available to us uses it; GM reports an open circuit as P057C or P057D depending on the line, type A with one trip, and sets the pedal position to 0 %. Brake detection then relies on the brake light switch.

Symptoms

• Check engine light on
• Cruise control and stop-start inoperative
• Possible power reduction

Most likely causes

• Connector at the sensor loose or corroded, pins pushed back
• 5 V reference, signal or ground line open
• Sensor faulty internally
• Engine or body module

What to check, in order

Start with the simplest. You can tick off each step.

1. Check the pedal and throttle connectors
2. Check the continuity of the wire between the component and the control module.
3. Use live data to confirm that both sensors rise smoothly and consistently
4. Clean the throttle if it has carbon buildup
5. Run the relearn procedure with the scanner if the manufacturer requires it
6. Replace the part identified by the diagnosis

Good to know

• Repair difficulty: medium
• It can trigger limp mode.

What each character of P057A means

• P: Powertrain: engine and transmission
• 0: Generic code: same on every make
• 5: Speed and idle
• 7A: Specific fault in that system

Frequently asked questions

Can I keep driving with code P057A?

Be careful: the car may suddenly lose power. If it goes into limp mode, get off the highway and calmly make your way to a repair shop.

What causes code P057A?

The most common causes are: connector at the sensor loose or corroded, pins pushed back; 5 V reference, signal or ground line open; sensor faulty internally.

Related codes

• P057BBrake Pedal Position Sensor A Circuit Range/Performance
• P057CBrake Pedal Position Sensor A Circuit Low
• P057DBrake Pedal Position Sensor A Circuit High
• P057EBrake Pedal Position Sensor A Circuit Intermittent/Erratic
• P0504Brake Switch A/B Correlation

Sources

• law.cornell.edu: 13 CCR 1968.2
• gsi.ext.gm.com: 18OBDG03A Engine Diagnostics
• gm-techlink.com

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.