C0040:64

Diagnostic Routine E

Diagnostic Overview

C0040:64

Refer to Wiring Diagram Set 31 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 wheel speed sensor input to determine if the brake pedal input is valid. As vehicle speed decreases, the ABS (Anti-Lock Brake System) module will look 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 (Anti-Lock Brake System) sets a DTC (Diagnostic Trouble Code). A brake pedal switch that is incorrectly installed 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






Visual Inspection and Diagnostic Pre-checks

- Make sure the stoplamp switch electrical connector is connected and free of corrosion and other contaminates.

- Make sure the stoplamp switch is installed correctly.

- Make sure the stoplamp switch is operating correctly.

Pinpoint Test

1. CHECK THE ABS (Anti-Lock Brake System) MODULE BRAKE ON/OFF (BOO_ABS) PID (Parameter Identification)

1. Using a scan tool, monitor the BOO_ABS PID (Parameter Identification) while pressing and releasing the brake pedal switch.

Does the PID (Parameter Identification) display ON when the pedal is applied and OFF when the pedal is released?






2. CHECK THE BRAKE PEDAL SWITCH ADJUSTMENT

1. Carry out the Brake Pedal Switch Adjustment. REFER to Brake Pedal Switch Adjustment .

Is the brake pedal switch correctly installed/adjusted?






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

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

2. Retrieve and record all ABS (Anti-Lock Brake System) module DTCs (Diagnostic Trouble Codes).

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






4. 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.

2. Retrieve and record all PCM (Powertrain Control Module) DTCs (Diagnostic Trouble Codes).

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






5. 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?