ANY OF THE FOLLOWING LIGHTS DO NOT TURN ON WITH THE MAIN POWER SWITCHED ON (READY OFF OR ON). (ABS WARNING LIGHT, BRAKE WARNING LIGHT, TCS/DSC OPERATION INDICATOR LIGHT, TCS OFF INDICATOR LIGHT) [ELECTRONICALLY CONTROLLED BRAKE SYSTEM]

id040309071500

Outline

Description	Any of the following lights do not turn on with the main power switched ON (READY off or on). (ABS warning light, brake warning light, TCS/DSC operation indicator light, TCS OFF indicator light)
Possible cause	•  Electronically controlled brake unit does not activate •  Communication error between electronically controlled brake unit and body control module (BCM) •  Communication error between body control module (BCM) and instrument cluster •  Instrument cluster malfunction •  Electronically controlled brake unit internal malfunction

Diagnostic Procedure

Step	Inspection	Results	Action
1	VERIFY OTHER WARNING LIGHT/INDICATOR LIGHT ON CONDITION •  Switch the main power ON (READY off or on). •  Are any warning lights/indicator lights other than the ABS warning light, brake warning light, TCS/DSC operation indicator light, and the TCS OFF indicator light turned on with the main power switched ON (READY off or on)?	Yes	Go to Step 4.
		No	Communication error is displayed on M-MDS screen: •  Go to the next step. Communication error is not displayed on M-MDS screen: •  Replace the instrument cluster.
*2	INSPECT INSTRUMENT CLUSTER POWER SUPPLY CIRCUIT FOR SHORT TO GROUND AND OPEN CIRCUIT •  Inspect the applicable circuit for a short to ground and open circuit. (See CIRCUIT INSPECTION.) •  Is the circuit normal?	Yes	Go to the next step.
		No	Repair or replace the malfunctioning location and perform the repair completion verification.
*3	INSPECT INSTRUMENT CLUSTER GROUND CIRCUIT FOR SHORT TO POWER SUPPLY AND OPEN CIRCUIT •  Inspect the applicable circuit for a short to power supply and open circuit. (See CIRCUIT INSPECTION.) •  Is the circuit normal?	Yes	Replace the instrument cluster and perform the repair completion verification. (Open circuit in instrument cluster internal circuit)
		No	Repair or replace the malfunctioning location and perform the repair completion verification.
4	VERIFY ELECTRONICALLY CONTROLLED BRAKE UNIT DTCs •  Verify the electronically controlled brake unit DTCs. (See DTC INSPECTION.) •  Is a DTC displayed?	Yes	Repair the malfunctioning location according to the applicable DTC troubleshooting. (See DTC TABLE [ELECTRONICALLY CONTROLLED BRAKE UNIT].)
		No	Communication error is displayed on M-MDS screen: •  Go to the next step. Communication error is not displayed on M-MDS screen: •  Go to Step 7.
*5	INSPECT ELECTRONICALLY CONTROLLED BRAKE UNIT POWER SUPPLY CIRCUIT FOR SHORT TO GROUND AND OPEN CIRCUIT •  Inspect the applicable circuit for a short to ground and open circuit. (See CIRCUIT INSPECTION.) •  Is the circuit normal?	Yes	Go to the next step.
		No	Repair or replace the malfunctioning location and perform the repair completion verification.
*6	INSPECT ELECTRONICALLY CONTROLLED BRAKE UNIT GROUND CIRCUIT FOR SHORT TO POWER SUPPLY AND OPEN CIRCUIT •  Inspect the applicable circuit for a short to power supply and open circuit. (See CIRCUIT INSPECTION.) •  Is the circuit normal?	Yes	Replace the electronically controlled brake unit and perform the repair completion verification. (Open circuit in electronically controlled brake unit internal circuit) (See ELECTRONICALLY CONTROLLED BRAKE UNIT REMOVAL/INSTALLATION [L.H.D.].) (See ELECTRONICALLY CONTROLLED BRAKE UNIT REMOVAL/INSTALLATION [R.H.D.].)
		No	Repair or replace the malfunctioning location and perform the repair completion verification.
7	INSPECT BODY CONTROL MODULE (BCM) FOR MALFUNCTION •  Perform the DTC inspection for the body control module (BCM). (See DTC INSPECTION.) •  Is a DTC displayed?	Yes	Repair the malfunctioning location according to the applicable DTC troubleshooting.
		No	Replace the instrument cluster and perform the repair completion verification.
Repair completion verification	VERIFY IF MALFUNCTION CAUSE IS CORRECTED •  Install/connect the part removed/disconnected during the troubleshooting procedure. •  Has the malfunction symptom been eliminated?	Yes	Complete the symptom troubleshooting. Explain repair contents to customer.
		No	Refer to the CAN (controller area network) malfunction diagnosis flow to inspect for a CAN communication error. (See CONTROLLER AREA NETWORK (CAN) MALFUNCTION DIAGNOSIS FLOW [L.H.D. (E)].) (See CONTROLLER AREA NETWORK (CAN) MALFUNCTION DIAGNOSIS FLOW [R.H.D.].) If the CAN communication is normal, perform the diagnosis from Step 1.