Some 2012-2019 Cruze; 2012-2020 Regal; and 2012-2025 Malibu, Equinox and Terrain models may experience low or reduced power under acceleration. DTCs P057B (Brake Pedal Position Sensor Performance), P057C (Brake Pedal Position Sensor Circuit Low Voltage) or P057E (Brake Pedal Position Sensor Circuit Erratic) may be set.
These conditions may be caused by an incorrect Brake Pedal Position (BPP) sensor signal input to the Engine Control Module (ECM), which may cause the ECM to read that the brake pedal is being applied when it is not. It may be necessary to adjust or replace the Brake Pedal Position sensor. (Fig. 5)
Fig. 5
View the BPP data in the ECM to help determine the value the ECM has learned for the brake pedal learned released voltage as well as the actual BPP voltage. With the brake pedal released, the actual BPP voltage should be equal to or close to the BPP Sensor Learned Released Position voltage.
- BPP Sensor (%) = 0% to 100% (should read 0% with brake pedal released)
- BPP Sensor (Voltage) = Voltage (typical voltage with pedal released is approximately 1 volt +/–3 volt)
- BPP Sensor Learned Released Position = Voltage (should equal the BPP sensor voltage with pedal released)
When the ECM has learned the BPP sensor learned released position voltage, the voltage should not change. The ECM will continuously monitor the voltage for a lower-than-expected value.
If there is a wiring or connection condition or an internal issue with the BPP sensor that would cause the ECM to see a lower value, the ECM will learn the lower value as the new learned released position. As a result, when the faulted condition is no longer present and the BPP voltage returns to the previously learned voltage, the ECM will interrupt this as the brake is applied. BPP apply percentage will be greater than 0. Turn off traction control or perform an ECM BPP learn to confirm the condition and temporarily correct the reduced engine power concern.
Check Wiring and Connections
Any wiring or connection condition that can cause a loss of voltage or lower than expected voltage on the 5v reference to the BPP sensor or signal return circuit to the ECM, such as a short to ground, terminal fretting or an intermittent open in the circuits, should be addressed.
BPP Sensor
To inspect, adjust, or replace the BPP, refer to Brake Pedal Position Sensor Replacement in the appropriate Service Information. If the BPP sensor is replaced, be sure to follow the procedure for the BPP sensor calibration.
– Thanks to Jonathan Johnson, Kurtis Hoezee, Rob Smith
