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NO.10 BRAKE SYSTEM WARNING LIGHT GOES ON AND OFF

BME040343000214
• When performing an asterisked (*) troubleshooting inspection, shake the wiring harness and connectors while doing the inspection to discover whether poor contact points are the cause of any intermittent malfunctions. If there is a problem, check to make sure connectors, terminals and wiring harness are connected correctly and undamaged.

10 | BRAKE system warning light goes on and off
[TROUBLESHOOTING HINTS] • Intermittent open circuit in BRAKE system warning light

Diagnostic procedure

STEP | INSPECTION | ACTION
--- | --- | ---
1 | • Is brake fluid level okay? | Yes | Go to next step.
No | Add brake fluid.
2 | • Inspect the following items using WDS or equivalent.

  - BRAKE_LMP (BRAKE system warning light)

• Is error message displayed regarding communication between ABS HU/CM and WDS or equivalent?
Yes
If a communication error message is displayed even after inspecting according to procedures displayed on the WDS or equivalent, go to Step 5.
No | Go to next step.
3 | • Inspect the following items using WDS or equivalent.

  - BRAKE_LMP (BRAKE system warning light)

• Drive vehicle under conditions in which warning light illuminates.
• Does BRAKE_LMP come ON when malfunction symptom happens again?
Yes
Replace ABS HU/CM (open or ground to short in ABS HU/CM).
No | Go to next step.
4 | • Disconnect the following connectors in order:

  - Parking brake switch connector.
  - Brake fluid level sensor connector

• Drive vehicle under conditions in which warning light illuminates.
• Does malfunction symptom happen again?
Yes
Inspect and repair following parts:
• Open in wiring harness between ABS HU/CM (terminal X) and instrument cluster (BRAKE system warning light)
• Short to ground in wiring harness between instrument cluster (BRAKE system warning light) and parking brake switch.
• Short to ground in wiring harness between instrument cluster (BRAKE system warning light) and brake fluid level sensor.
• If above inspection are okay, replace instrument cluster (open or ground to short in instrument cluster).
No | Replace parking brake switch and/or brake fluid level sensor (shorted to some internal part).
*5 | • Disconnect ABS HU/CM connector. Connect SST (adapter harness) (vehicle harness side only). • Is there continuity between SST (adapter harness) connector terminal T and DLC-2? | Yes | Go to next step.
No | Repair wiring harness between ABS HU/CM and DLC-2.
*6 | • Is voltage approximately 12 V at SST (adapter harness) connector terminal T? | Yes | Repair wiring harness between ABS HU/CM and DLC-2.
No | Go to next step.
*7 | • Is there continuity between SST (adapter harness) connector terminal T and ground? | Yes | Repair wiring harness between ABS HU/CM and DLC-2.
No | Inspect and repair wiring harness for ABS HU/CM power supply (terminal Z) and ground 1 (terminal AA)).