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DTC C1128:4A [ELECTRONICALLY CONTROLLED BRAKE UNIT]

id0402c6008100

Outline

System malfunction location

Electric parking brake switch

Detection condition

•  The electronically controlled brake unit detects that the electric parking brake switch is not connected.

Fail-safe

Refer to “DTC Table” and “Fail-safe Function Malfunction Contents Table”. (See DTC TABLE [ELECTRONICALLY CONTROLLED BRAKE UNIT].)

Possible cause

•  Electric parking brake switch connector or terminal malfunction

•  Electric parking brake switch malfunction

•  Electronically controlled brake unit connector or terminals malfunction

•  Open circuit in electric parking brake switch signal circuit

•  Electronically controlled brake unit malfunction

System malfunction location	Electric parking brake switch
Detection condition	• The electronically controlled brake unit detects that the electric parking brake switch is not connected.
Fail-safe	Refer to “DTC Table” and “Fail-safe Function Malfunction Contents Table”. (See DTC TABLE [ELECTRONICALLY CONTROLLED BRAKE UNIT].)
Possible cause	• Electric parking brake switch connector or terminal malfunction • Electric parking brake switch malfunction • Electronically controlled brake unit connector or terminals malfunction • Open circuit in electric parking brake switch signal circuit • Electronically controlled brake unit malfunction

Diagnostic Procedure

Step

Inspection

Results

Action

1

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.

2

INSPECT ELECTRIC PARKING BRAKE SWITCH FOR MALFUNCTION

•  Inspect the applicable part.
(See ELECTRIC PARKING BRAKE 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.)

3

INSPECT ELECTRONICALLY CONTROLLED BRAKE UNIT 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

INSPECT ELECTRIC PARKING BRAKE SWITCH SIGNAL CIRCUIT FOR OPEN CIRCUIT

•  Inspect the applicable circuit for 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.

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.)

•  Perform the following procedure 3 times or more.

―  Pull up the electric parking brake switch to operate the electric parking brake.

―  Press down the electric parking brake switch to release the electric parking brake.

•  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.

Step	Inspection	Results	Action
1	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.
1		No	Repair or replace the malfunctioning location and perform the repair completion verification.
2	INSPECT ELECTRIC PARKING BRAKE SWITCH FOR MALFUNCTION • Inspect the applicable part. (See ELECTRIC PARKING BRAKE SWITCH INSPECTION.) • Is the part normal?	Yes	Go to the next step.
2		No	Repair or replace the malfunctioning location and perform the repair completion verification. (See ELECTRIC PARKING BRAKE SWITCH REMOVAL/INSTALLATION.)
3	INSPECT ELECTRONICALLY CONTROLLED BRAKE UNIT CONNECTOR FOR MALFUNCTION • Inspect the applicable connector and terminal. (See CONNECTOR INSPECTION.) • Are the connector and terminal normal?	Yes	Go to the next step.
3		No	Repair or replace the malfunctioning location and perform the repair completion verification.
4	INSPECT ELECTRIC PARKING BRAKE SWITCH SIGNAL CIRCUIT FOR OPEN CIRCUIT • Inspect the applicable circuit for open circuit. (See CIRCUIT INSPECTION.) • Is the circuit normal?	Yes	Go to the next step.
4		No	Repair or replace the malfunctioning location and perform the repair completion verification.
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.) • Perform the following procedure 3 times or more. ― Pull up the electric parking brake switch to operate the electric parking brake. ― Press down the electric parking brake switch to release the electric parking brake. • 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.].)
Repair completion verification 1		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.
Repair completion verification 2		No	DTC troubleshooting completed.