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DTC C1139:64 [ELECTRONICALLY CONTROLLED BRAKE UNIT]

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Outline

System malfunction location	AUTOHOLD switch
Detection condition	•  The electronically controlled brake unit detects that the AUTOHOLD switch via CAN communication is on (stuck on) for 30 s or more.
Fail-safe	Refer to “DTC Table” and “Fail-safe Function Malfunction Contents Table”. (See DTC TABLE [ELECTRONICALLY CONTROLLED BRAKE UNIT].)
Possible cause	Caution •  When the AUTOHOLD switch is continuously pressed down for a long period, DTCs may be detected. Therefore, always verify that DTCs being detected are due to how the customer has operated the switch. •  Electric parking brake switch connector or terminal malfunction •  Electric parking brake switch malfunction ―  AUTOHOLD switch malfunction •  Short to ground in AUTOHOLD switch signal circuit •  Electrical supply unit (ESU) malfunction •  Electronically controlled brake unit malfunction

Diagnostic Procedure

Step	Inspection	Results	Action
1	ASK CUSTOMER IF AUTOHOLD SWITCH HAS BEEN PRESSED DOWN CONTINUOUSLY FOR 30 S OR MORE •  Ask the customer if the AUTOHOLD switch has been pressed down continuously for 30 s or more. •  Has the AUTOHOLD switch been pulled up/pressed down continuously for 30 s or more?	Yes	System is normal. (Explain to the customer that it is not necessary to continuously press down the AUTOHOLD switch to operate/release the AUTOHOLD system.)
		No	Go to the next step.
2	DETERMINE MALFUNCTIONING LOCATION •  Perform the PID/data monitor inspection and display the following item. (See PID/DATA MONITOR INSPECTION.) (See PID/DATA MONITOR TABLE [ELECTRICAL SUPPLY UNIT (ESU) (E)].) Electrical supply unit (ESU) ―  AUTO_HOLD_SW •  Does the data monitor value change in conjunction with the AUTOHOLD switch operation?	Yes	Go to Step 7.
		No	Go to the next step.
3	INSPECT ELECTRIC PARKING BRAKE SWITCH CONNECTOR FOR MALFUNCTION •  Inspect the applicable connector and terminal. (See CONNECTOR INSPECTION.) •  Are the connector and terminal normal?	Yes	Go to the next step.
		No	Repair or replace the malfunctioning location and perform the repair completion verification.
4	VISUALLY INSPECT AUTOHOLD SWITCH FOR MALFUNCTION •  Visually verify the AUTOHOLD switch for the following. ―  Interference with surrounding parts ―  Foreign matter penetration in movable parts •  Is the AUTOHOLD switch normal?	Yes	Go to the next step.
		No	Interference with surrounding parts: •  Install the electric parking brake switch correctly. (See ELECTRIC PARKING BRAKE SWITCH REMOVAL/INSTALLATION.) ―  If the malfunction recurs, replace the electric parking brake switch. (See ELECTRIC PARKING BRAKE SWITCH REMOVAL/INSTALLATION.) •  Perform the repair completion verification. Foreign matter has penetrated movable parts: •  Remove the foreign matter and perform the repair completion verification.
5	INSPECT AUTOHOLD SWITCH FOR MALFUNCTION •  Inspect the applicable part. (See AUTO HOLD SWITCH INSPECTION.) •  Is the part normal?	Yes	Go to the next step.
		No	Repair or replace the malfunctioning location and perform the repair completion verification. (See ELECTRIC PARKING BRAKE SWITCH REMOVAL/INSTALLATION.)
6	INSPECT AUTOHOLD SWITCH SIGNAL CIRCUIT FOR SHORT TO GROUND •  Inspect the applicable circuit for a short to ground. (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.
7	INSPECT ELECTRICAL SUPPLY UNIT (ESU) FOR MALFUNCTION DEPENDING ON REPEATABILITY •  Install/connect the part removed/disconnected during the troubleshooting procedure. •  Clear the DTC recorded in the memory. (See CLEARING DTC.) •  Operate the AUTOHOLD switch 2 or 3 times, and then finally turn it off. •  Perform the DTC inspection for the electronically controlled brake unit. (See DTC INSPECTION.) •  Is the same Pending DTC present?	Yes	Refer to the controller area network (CAN) malfunction diagnosis flow to inspect for a CAN communication error. (See CONTROLLER AREA NETWORK (CAN) MALFUNCTION DIAGNOSIS FLOW [(E)].) If the CAN communication is normal, replace the malfunctioning location and perform the repair completion verification. (See ELECTRICAL SUPPLY UNIT (ESU) REMOVAL/INSTALLATION.)
		No	Go to repair completion verification 2.
Repair completion verification 1	VERIFY THAT VEHICLE IS REPAIRED •  Install/connect the part removed/disconnected during the troubleshooting procedure. •  Clear the DTC recorded in the memory. (See CLEARING DTC.) •  Operate the AUTOHOLD switch 2 or 3 times, and then finally turn it off. •  Perform the DTC inspection for the electronically controlled brake unit. (See DTC INSPECTION.) •  Is the same Pending DTC present?	Yes	Refer to the controller area network (CAN) malfunction diagnosis flow to inspect for a CAN communication error. (See CONTROLLER AREA NETWORK (CAN) MALFUNCTION DIAGNOSIS FLOW [(E)].) If the CAN communication is normal, perform the diagnosis from Step 1. •  If the malfunction recurs, replace the electronically controlled brake unit, then go to the next step. (See ELECTRONICALLY CONTROLLED BRAKE UNIT REMOVAL/INSTALLATION [L.H.D.].) (See ELECTRONICALLY CONTROLLED BRAKE UNIT REMOVAL/INSTALLATION [R.H.D.].)
		No	Go to the next step.
Repair completion verification 2	VERIFY IF OTHER DTCs DISPLAYED •  Perform the DTC inspection. (See DTC INSPECTION.) •  Are any DTCs displayed?	Yes	Repair the malfunctioning location according to the applicable DTC troubleshooting.
		No	DTC troubleshooting completed.