Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Normal Operation and Fault Conditions
The ABS module receives BPP switch input from the PCM through the GWM over the HS-CAN. The ABS module compares this information against brake fluid pressure input to determine if the BPP switch input is valid. An incorrectly installed BPP switch can cause a signal plausibility concern. An implausible signal can also be created if a driver is resting one foot on the brake pedal while using the other foot to press the accelerator.
| DTC | Description | Fault Trigger Conditions |
|---|---|---|
| C0040:24 | Brake Pedal Switch "A": Signal Stuck High | There are 2 conditions which can cause this DTC to set in the ABS module. The first condition is if the PCM CAN messages indicate the brake pedal and accelerator pedals are pressed, vehicle speed is above 10 km/h (6 mph) and the brake fluid hydraulic pressure sensor in the HCU indicates less than 500 kPa (5 bar) for more than 60 seconds. The second condition is if the PCM CAN messages indicate the brake pedal and accelerator pedals are pressed and vehicle speed is greater than 10 km/h (6 mph) for more than 30 seconds. |
| C0040:64 | Brake Pedal Switch "A": Signal Plausibility Failure | This DTC sets in continuous memory in the ABS module if the PCM HS-CAN messages indicate the brake pedal is not being pressed, but brake hydraulic pressure is over 30 bar (435 psi) for more than 1 second. |
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.