Pinpoint Test B: DTC C1446
Anti-Lock Control
Pinpoint Tests
Pinpoint Test B: DTC C1446
Refer to Wiring Diagram Set 42, Vehicle Dynamic Systems for schematic and connector information. Diagrams By Number
Normal Operation
The ABS module receives brake pedal input from the PCM over the High Speed Controller Area Network (HS-CAN) bus. The ABS module compares this information against other inputs (wheel speed signals and vehicle speed signal) to determine if the brake pedal input is valid.
- DTC C1446 (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 and vehicle speed signal), DTC C1446 will be set.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Brake pedal switch
PINPOINT TEST B: DTC C1446
NOTICE: Use the Flex Probe Kit for all test connections to prevent damage to the wiring terminals. Do not use standard multi-meter probes.
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B1 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 B2.
No
REFER to Exterior Lighting Testing and Inspection for further diagnosis of the stoplamps.
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B2 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. Anti-Lock Control
No
GO to B3.
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B3 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 Computers and Control Systems to diagnose the PCM.
No
GO to B4.
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B4 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 B5.
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B5 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 Module Communications Network Testing and Inspection to diagnose the HS-CAN bus.
No
REFER to Exterior Lighting Testing and Inspection to diagnose the stoplamp switch.
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