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Normal Operation and Fault Conditions

WARNING: This page is about a different car, the 2018 Lincoln Navigator. However, it is still accessible from the selected car via links, so may be relevant.

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. 

PPT AC ABS MODULE DTC FAULT TRIGGER CONDITIONS

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.