Pinpoint Test A: DTC B1483

Anti-Lock Control

Pinpoint Tests

Pinpoint Test A: DTC B1483

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

Normal Operation

When the brake pedal is pressed, the Brake Pedal Position (BPP) switch opens and interrupts a voltage signal that is sent to the PCM. When the PCM detects this interruption, it sends a message over the High Speed Controller Area Network (HS-CAN) bus indicating that the brake pedal has been pressed. The PCM uses the BPP switch information for the speed control system. The ABS module receives the BPP switch information from the PCM over the HS-CAN bus.

The BPP is also known as the stoplamp switch.

- DTC B1483 (Brake Pedal Input Open Circuit) - The ABS module compares the BPP message against other inputs (brake pressure and wheel speed) and if the message does not match the other inputs and there are no DTCs present for those inputs, DTC B1483 will be set.

This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- BPP switch
- PCM
- ABS module



PINPOINT TEST A: DTC B1483

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

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A1 CHECK FOR PCM DTCs


- Ignition ON.
- Enter the following diagnostic mode on the scan tool: KOEO Self Test - PCM .
- Retrieve and record any PCM DTCs.
- Are any DTCs present in the PCM?

Yes
REFER to the DTC Chart in Body Control Systems. Diagnostic Trouble Code (DTC) Chart

No
GO to A2.

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A2 CHECK THE ABS MODULE DTCs


- Review the DTCs recorded during Inspection and Verification.
- Are DTCs U0100 and/or U0401 also present?

Yes
DIAGNOSE U0100 and/or U0401 before diagnosing B1483. REFER to the ABS Module DTC Chart. Diagnostic Trouble Code Tests and Associated Procedures

No
If DTCs C1288 and/or C1440 are present, GO to Pinpoint Test I. Pinpoint Test I: DTC C1996

If no other DTCs are present, GO to A3.

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A3 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 agree with the pedal position?

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

No
GO to A4.

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A4 CHECK THE PCM BOO PID


- Enter the following diagnostic mode on the scan tool: DataLogger - PCM .
- Monitor the BOO PID while pressing and releasing the brake pedal.
- Does the PID agree with the pedal position?

Yes
REFER to Information Bus to diagnose the communication concern.

No
REFER to Fire Suppression System and diagnose the speed control deactivation switch.

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