NO.4 BRAKE SYSTEM WARNING LIGHT DOES NOT ILLUMINATE WITH SWITCH THE IGNITION TO ON [ABS]

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4	BRAKE system warning light does not illuminate with switch the ignition to on.
[TROUBLESHOOTING HINTS] •  Malfunction of instrument cluster or ABS HU/CM •  Communication error between ABS HU/CM and instrument cluster •  ABS HU/CM does not operate

Diagnostic procedure

STEP	INSPECTION		ACTION
1	CONFIRM ABS HU/CM DTC •  Retrieve the ABS HU/CM DTC using the M-MDS. (See ON-BOARD DIAGNOSIS [ABS].) •  Is there any DTC retrieved?	Yes	Perform the applicable DTC troubleshooting procedure.
		No	If communication error message is displayed on M-MDS screen, go to the next step. If communication error message is not displayed, go to Step 5.
2	INSPECT ABS POWER SUPPLY FUSE •  Is ABS power supply fuse normal?	Yes	Go to the next step.
		No	Inspect for a short to ground on blown fuse’s circuit. Repair or replace as necessary. Install appropriate amperage fuse.
*3	VERIFY WHETHER MALFUNCTION IS IN WIRING HARNESS (BETWEEN ABS HU/CM POWER SUPPLY AND ABS HU/CM FOR CONTINUITY) OR ELSEWHERE •  Switch the ignition to ON. •  Measure the voltage at ABS HU/CM terminal AF. •  Is voltage approx. 12 V?	Yes	Go to the next step.
		No	Inspect for open circuit between ABS HU/CM and ignition. Repair or replace as necessary.
*4	VERIFY WHETHER MALFUNCTION IS IN WIRING HARNESS (BETWEEN INSTRUMENT CLUSTER AND GND FOR CONTINUITY) OR ABS HU/CM •  Switch the ignition to off. •  Disconnect the instrument cluster. •  Verify continuity between the harness-side connector terminal A and GND. •  Is there continuity?	Yes	Replace the ABS HU/CM. (Internal malfunction.) (See ABS HU/CM REMOVAL/INSTALLATION.)
		No	Repair or replace malfunctioning part for open circuit and poor contact in GND point.
5	VERIFY WHERE MALFUNCTION IS IN WARNING LIGHTS AND INDICATOR LIGHTS’ COMMON POWER SUPPLY, OR IN OTHER WARNING LIGHTS AND INDICATOR LIGHTS •  Turn on all warning lights and indicator lights using the instrument cluster PID WL+IL of active command modes using the M-MDS. (See ACTIVE COMMAND MODES INSPECTION [INSTRUMENT CLUSTER].) •  Do other warning and indicator lights illuminate?	Yes	Go to the next step.
		No	Replace the instrument cluster. (See INSTRUMENT CLUSTER REMOVAL/INSTALLATION.)
6	CONFIRM INSTRUMENT CLUSTER CM DTC •  Retrieve the instrument cluster DTC using the M-MDS. (See DTC INSPECTION [INSTRUMENT CLUSTER].) •  Is there any DTC retrieved?	Yes	Perform the applicable DTC troubleshooting procedure. (See DTC TABLE [INSTRUMENT CLUSTER].)
		No	Replace the instrument cluster. (See INSTRUMENT CLUSTER REMOVAL/INSTALLATION.)