NO.6 BRAKE SYSTEM WARNING LIGHT STAYS ON 4 S OR MORE WITH SWITCH THE IGNITION TO ON (PARKING BRAKE IS RELEASED) [ABS]

id0403a5950800

6	Brake system warning light stays on 4 s or more with switch the ignition to ON (Parking brake is released)
Possible cause	•  Brake fluid level is low •  ABS HU/CM DTC is stored •  Instrument cluster malfunction •  Parking brake switch malfunction •  Brake fluid level sensor malfunction •  Short to ground in wiring harness between parking brake switch and BCM •  Short to ground in wiring harness between brake fluid level sensor and BCM •  BCM malfunction

Diagnostic procedure

STEP	INSPECTION		ACTION
1	INSPECT BRAKE FLUID LEVEL •  Inspect the brake fluid level. •  Is the brake fluid level normal?	Yes	Go to the next step.
		No	Add the brake fluid.
2	CONFIRM INSTRUMENT CLUSTER DTC •  Retrieve the instrument cluster DTC using the M-MDS. (See DTC INSPECTION [INSTRUMENT CLUSTER].) •  Is the DTC U0415:92 present?	Yes	Go to the next step.
		No	Go to Step 4.
3	CONFIRM ABS HU/CM DTC •  Retrieve the ABS HU/CM DTC using the M-MDS. (See ON-BOARD DIAGNOSIS [ABS].) •  Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See ON-BOARD DIAGNOSIS [ABS].)
		No	Go to the next step.
4	INSPECT WHETHER MALFUNCTION IS IN INSTRUMENT CLUSTER OR ELSEWHERE •  Release the parking brake. •  Turn on all the warning light and indicator light using the M-MDS simulation function WL+IL. (See ACTIVE COMMAND MODES INSPECTION [INSTRUMENT CLUSTER].) •  Does the ABS warning light turn off?	Yes	Go to the next step.
		No	Replace the instrument cluster. (See INSTRUMENT CLUSTER REMOVAL/INSTALLATION.)
5	INSPECT WHETHER MALFUNCTION IS IN BRAKE SYSTEM WARNING LIGHT RELATED SWITCHES OR ELSE WHERE •  Inspect the following parts for continuity: ―  Parking brake switch (See PARKING BRAKE SWITCH INSPECTION.) ―  Brake fluid level sensor (See BRAKE FLUID LEVEL SENSOR INSPECTION.) •  Is the continuity condition normal?	Yes	Go to the next step.
		No	Repair or replace the malfunctioning part according to the inspection results. (See PARKING BRAKE LEVER REMOVAL/INSTALLATION.) (See MASTER CYLINDER REMOVAL/INSTALLATION [MZR 1.5, MZR 1.6, MZR 2.0, MZR 2.5, MZ-CD 1.6, MZR-CD 2.2].)
*6	INSPECT FOR SHORT TO GROUND IN WIRING HARNESS BETWEEN BCM AND BRAKE SYSTEM WARNING LIGHT RELATED SWITCHES •  Inspect for continuity between the following terminals (wiring harness-side) and body ground: ―  Parking switch terminal A ―  Brake fluid level sensor terminal B •  Is there continuity?	Yes	Repair or replace the wiring harness for a possible short to ground.
		No	Replace the BCM. (See BODY CONTROL MODULE (BCM) REMOVAL/INSTALLATION [L.H.D.].) (See BODY CONTROL MODULE (BCM) REMOVAL/INSTALLATION [R.H.D.].)