C0040

Diagnostic Routine E

Diagnostic Overview

C0040:64

Refer to Wiring Diagram Set 42 for schematic and connector information Electrical Diagrams.

Normal Operation and Fault Conditions

The ABS (Anti-Lock Brake System) module receives brake pedal switch input from the PCM (Powertrain Control Module) over the HS-CAN (High Speed Controller Area Network). The ABS (Anti-Lock Brake System) module compares this information against other inputs (wheel speed signals, vehicle speed signal, brake pressure input) to determine if the brake pedal input is valid. A brake pedal switch that is incorrectly installed can cause a signal plausibility concern.

DTC Fault Trigger Conditions






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 stoplamp switch is operating correctly.

Pinpoint Test

1. CHECK THE STOPLAMPS FOR CORRECT OPERATION

1. Inspect the brake pedal position switch and make sure it is installed correctly. Check the stoplamps for correct operation by pressing and releasing the brake pedal and observing the stoplamps.

Do the stoplamps operate correctly?






2. CHECK THE ABS (Anti-Lock Brake System) MODULE DTCs (Diagnostic Trouble Codes)

1. Ignition ON.

2. Using a scan tool, carry out the ABS (Anti-Lock Brake System) module self-test.

Are any communication (U-code) DTCs (Diagnostic Trouble Codes) present?






3. CHECK THE PCM (Powertrain Control Module) FOR DTCs (Diagnostic Trouble Codes)

1. Using a scan tool, carry out the PCM (Powertrain Control Module) KOEO (Key ON Engine OFF) self-test.

Are any DTCs (Diagnostic Trouble Codes) present in the PCM (Powertrain Control Module)?






4. CHECK FOR CORRECT ABS (Anti-Lock Brake System) MODULE OPERATION

1. Ignition OFF.

2. Disconnect and inspect the ABS (Anti-Lock Brake System) Module electrical connector.

3. Repair:

- corrosion (install new connector or terminal - clean module pins)
- damaged or bent pins - install new terminals/pins
- pushed-out pins - install new pins as necessary

4. Connect the ABS (Anti-Lock Brake System) Module electrical connector. Make sure it seats and latches correctly.

5. Operate the system and determine if the concern is still present.

Is the concern still present?