Pinpoint Test P: DTC C1446
Anti-Lock Control - Traction Control and Stability Assist
Pinpoint Tests
Pinpoint Test P: 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 the brake fluid level information and the Brake Pedal Position (BPP) switch information over the High Speed Controller Area Network (HS-CAN) bus. The PCM provides the BPP switch information and the Instrument Panel Cluster (IPC) provides the brake fluid level information.
The BPP switch is also known as the stoplamp switch.
- DTC C1446 (Brake Switch Circuit Failure) - If during normal operation or the on-demand self test the ABS module does not receive the brake fluid level message and/or the BPP switch message, or if the BPP switch message is inconsistent with other sensor information, DTC C1446 will be set.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- BPP switch
- IPC
- PCM
PINPOINT TEST P: DTC C1446
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P1 CHECK THE RED BRAKE WARNING INDICATOR OPERATION
- Monitor the red brake warning indicator in the IPC.
- Ignition OFF.
- Ignition ON.
- Verify the red brake warning indicator illuminates for a few seconds and then extinguishes.
- Does the warning indicator illuminate for a few seconds and then extinguish?
Yes
GO to P2.
No
REFER to Instrument Panel, Gauges and Warning Indicators to diagnose the red brake warning indicator.
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P2 CHECK THE STOPLAMP OPERATION
- Verify the stoplamps operate correctly while pressing and releasing the brake pedal.
- Do the stoplamps operate correctly?
Yes
GO to P3.
No
REFER to Lighting and Horns to diagnose the stoplamps.
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P3 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 - Traction Control and Stability Assist
No
GO to P4.
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P4 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 the PCM DTCs.
- Are any DTCs present in the PCM?
Yes
REFER to Computers and Control Systems Information to diagnose the PCM.
No
GO to P5.
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P5 MONITOR THE ABS MODULE BRAKE ON/OFF (BOO_ABS) PID
- Enter the following diagnostic mode on the scan tool: DataLogger - ABS Module.
- Press and release the brake pedal while monitoring the BOO_ABS PID.
- Does the PID display ON with the brake pedal applied and OFF with the brake pedal released?
Yes
The system is operating correctly at this time. CLEAR the DTCs. REPEAT the self-test.
No
GO to P6.
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P6 MONITOR THE PCM BOO1 PID
- Enter the following diagnostic mode on the scan tool: DataLogger - PCM.
- Press and release the brake pedal while monitoring the BOO1 PID.
- Does the PID display ON with the brake pedal applied and OFF with the brake pedal released?
Yes
REFER to Information Bus to diagnose the HS-CAN bus.
No
REFER to Lighting and Horns to diagnose the stoplamp switch.
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