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.
Pinpoint Test C : C0040:64: Notes
Refer to Cruise Control for schematic and connector information.
Normal Operation and Fault Conditions
The ABS module receives brake pedal switch input from the PCM over the HS-CAN. The ABS module compares this information against wheel speed sensor input to determine if the brake pedal input is valid. As vehicle speed decreases, the ABS module looks for a change in the brake pedal switch input, if vehicle speed decreases but there is no change in the brake pedal switch, the ABS sets a DTC. An incorrectly installed brake pedal switch can cause a signal plausibility concern. Also, an implausible signal can been created if a driver is resting one foot on the brake pedal while using the other foot to press the accelerator.
DTC Fault Trigger Conditions
| DTC | Description | Fault Trigger Conditions |
|---|---|---|
| C0040:64 | Brake Pedal Switch "A": Signal Plausibility Failure | This DTC sets in continuous memory if brake pedal switch input is continuously active for more than 6 minutes when driving faster than 20 km/h (12 mph) or after accelerating up to a speed greater than 40 km/h (25 mph) and decelerating down to a speed less than 3 km/h (2 mph) 4 times with no change in brake pedal switch input. |
Possible Causes
- Brake pedal (stoplamp) switch
- Communication concern
- ABS module
Visual Inspection and Diagnostic Pre-checks
- Make sure the stoplamp switch electrical connector is connected and free of corrosion and other contaminants.
- Make sure the stoplamp switch is installed correctly.
- Make sure the stoplamps are operating correctly.
Use the Manual With the Right Hardware
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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.
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