C0040

Anti-Lock Control

Pinpoint Test D: DTC C0040:64

Refer to Wiring Diagrams Set 42, Vehicle Dynamic Systems for schematic and connector information. Electrical Diagrams

Normal Operation

The ABS module receives brake pedal input from the PCM over the High Speed Controller Area Network (HS-CAN). The ABS module compares this information against other inputs (wheel speed signals, vehicle speed signal, brake pressure transducer) to determine if the brake pedal input is valid.

- DTC C0040:64 (Brake Switch Circuit Failure)- If, during normal operation or the on-demand self test, the ABS module cannot detect the brake pedal input or if the brake pedal input does not match information from other sensors (wheel speed signals, vehicle speed signal, brake pressure transducer), DTC C0040:64 will be set.

This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors

- Brake pedal switch

PINPOINT TEST D : DTC C0040:64

NOTICE: Use the Flex Probe Kit for all test connections to prevent damage to the wiring terminals. Do not use standard multi-meter probes.

D1 VERIFY CORRECT STOPLAMP SWITCH INSTALLATION

- Check the stoplamp switch for correct installation.

Is the stoplamp switch correctly installed?

Yes
GO to D2.

No
REMOVE the stoplamp switch and INSTALL it correctly. CLEAR the DTCs. TEST DRIVE the vehicle above 40 km/h (25 mph) and CARRY OUT 4 complete stops. REPEAT the self-test.

D2 CHECK THE STOPLAMPS FOR CORRECT OPERATION

- Check the stoplamps for correct operation by pressing and releasing the brake pedal and observing the stoplamps.

Do the stoplamps operate correctly?

Yes
GO to D3.

No
REFER to Lighting and Horns for further diagnosis of the stoplamps.

D3 CHECK THE ABS MODULE DTCs

- Review the ABS module DTCs retrieved during Inspection and Verification.

Are any communication (U-code) DTCs present?

Yes
GO to the ABS Module DTC Chart and diagnose the U-code DTCs. Antilock Brakes / Traction Control Systems

No
GO to D4.

D4 CHECK THE PCM FOR DTCs

- Connect the scan tool.

- Ignition ON.

- Enter the following diagnostic mode on the scan tool: Self Test- PCM.

- Retrieve and record any PCM DTCs.

Are any DTCs present in the PCM?

Yes
REFER to the Computers and Control Systems Information to diagnose the PCM.

No
GO to D5.

D5 VERIFY DTC RESETS

- Using a scan tool, clear all ABS module DTCs.

- Ignition OFF.

- Ignition ON.

- Press and release the brake pedal 3 times.

- Enter the following diagnostic mode on the scan tool: Self Test- ABS Module.

Is DTC C0040:64 present?

Yes
GO to D6.

No
The fault is no longer present. The fault could have been caused by the brake pedal being pressed for greater than 6 minutes and the vehicle speed was greater than 20 km/h (12 mph).

D6 CHECK THE ABS MODULE BRAKE ON/OFF (BOO_ABS) PID

- Enter the following diagnostic mode on the scan tool: DataLogger- ABS Module.

- Monitor the BOO_ABS PID while pressing and releasing the brake pedal.

Does the PID display match the brake pedal position?

Yes
The system is operating correctly at this time. CLEAR the DTCs. REPEAT the self-test.

No
GO to D7.

D7 CHECK THE PCM BRAKE ON/OFF (BOO1) PID

- Enter the following diagnostic mode on the scan tool: DataLogger- PCM.

- Monitor the BOO1 PID while pressing and releasing the brake pedal.

Does the PID display match the brake pedal position?

Yes
REFER to Information Bus to diagnose the HS-CAN (High Speed Controller Area Network).

No
REFER to Lighting and Horns to diagnose the stoplamp switch.