Test J: The Brake Warning Indicator Is Always On

PINPOINT TEST J: THE BRAKE WARNING INDICATOR IS ALWAYS ON

Normal Operation
When the parking brake is applied, circuit CCB09 (GY/BU), to the SJB, is grounded by the parking brake switch through circuit GD143 (BK/VT). The SJB receives the ground signal and sends the instrument cluster (IC) a message over the medium speed controller area network (MS-CAN) to illuminate the brake warning indicator. The brake fluid level switch is hardwired to the ABS module through circuits CMC19 (GY/VT) and RMC19 (YE/GY). The brake fluid level switch is grounded through circuit GD120 (BK/GN). The ABS module monitors the brake fluid level and when the brake fluid level is low or a base brake system concern is detected, the ABS module sends a signal to the instrument cluster (IC) over the high speed controller area network (HS-CAN) to illuminate the brake warning indicator.

NOTE: When the ABS module detects an electronic brake distribution (EBD) fault, the ABS module sends a message to the instrument cluster (IC). Whenever the instrument cluster (IC) receives an EBD message from the ABS module, the instrument cluster (IC) turns on both the brake warning indicator and the ABS warning indicator simultaneously.

- DTC C1769 (Park Brake Apply Switch Circuit Short to Ground) - sets on-demand if the SJB detects a short to ground on the parking brake switch input circuit CCB09 (GY/BU).

This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Parking brake switch
- Brake fluid level switch (part of the master cylinder)
- SJB
- ABS module
- Instrument cluster (IC)

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J5-J6:

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J11: