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DTC C0049:7A [ELECTRONICALLY CONTROLLED BRAKE UNIT]

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Outline

System malfunction location

Brake fluid leakage or trapped air

Detection condition

•  The electronically controlled brake unit detects brake fluid leakage.

Fail-safe

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

Possible cause

•  Insufficient brake fluid level

•  Brake pipe and brake hose malfunction

―  Brake fluid leakage

•  Trapped air

•  Short circuit in brake fluid level sensor signal circuit

•  Brake fluid level sensor malfunction

•  Electronically controlled brake unit malfunction

―  Brake fluid leakage

System malfunction location	Brake fluid leakage or trapped air
Detection condition	• The electronically controlled brake unit detects brake fluid leakage.
Fail-safe	Refer to “DTC Table” and “Fail-safe Function Malfunction Contents Table”. (See DTC TABLE [ELECTRONICALLY CONTROLLED BRAKE UNIT].)
Possible cause	• Insufficient brake fluid level • Brake pipe and brake hose malfunction ― Brake fluid leakage • Trapped air • Short circuit in brake fluid level sensor signal circuit • Brake fluid level sensor malfunction • Electronically controlled brake unit malfunction ― Brake fluid leakage

Diagnostic Procedure

Step

Inspection

Results

Action

1

INSPECT BRAKE FLUID LEVEL

•  Inspect the brake fluid level.
(See BRAKE FLUID INSPECTION [(E)].)

•  Is the brake fluid level normal?

Yes

Go to the next step.

No

Add genuine brake fluid and go to the next step.

2

INSPECT BRAKE PIPE AND BRAKE HOSE FOR BRAKE FLUID LEAKAGE

•  Perform the brake fluid leakage inspection for the brake pipe and brake hose.

•  Is there brake fluid leakage?

Yes

Repair or replace the malfunctioning location and perform the repair completion verification.

(See FRONT BRAKE HOSE REMOVAL/INSTALLATION [(E)].)

(See REAR BRAKE HOSE REMOVAL/INSTALLATION [(E)].)

No

Go to the next step.

3

INSPECT ELECTRONICALLY CONTROLLED BRAKE UNIT FOR BRAKE FLUID LEAKAGE

•  Remove the brake pedal and inspect the electronically controlled brake unit for brake fluid leakage.

•  Is there brake fluid leakage?

Yes

Repair or replace the malfunctioning location and perform the repair completion verification 2.

(See ELECTRONICALLY CONTROLLED BRAKE UNIT REMOVAL/INSTALLATION [R.H.D.].)

(See ELECTRONICALLY CONTROLLED BRAKE UNIT REMOVAL/INSTALLATION [L.H.D.].)

No

Go to the next step.

4

VERIFY IF AIR IS TRAPPED IN BRAKE LINE

•  Select the following items from the initialization screen of the M-MDS.

1.  “Toolbox”

2.  “Work Support”

3.  “BRAKES”

4.  “Self-Diagnosing Brake Line”

•  Perform the Self-Diagnosing Brake Line according to the directions on the screen.

•  Is the result normal?

Yes

Go to the next step.

No

Bleed the air from the brake fluid according to the diagnostic result, and go to the repair completion verification.

(See BRAKE FLUID AIR BLEEDING [(E)].)

5

INSPECT BRAKE FLUID LEVEL SENSOR SIGNAL CIRCUITS FOR SHORT CIRCUIT

•  Inspect the applicable circuits for short 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 BRAKE FLUID LEVEL SENSOR FOR MALFUNCTION

•  Inspect the applicable part.
(See BRAKE FLUID LEVEL SENSOR INSPECTION [(E)].)

•  Is the part normal?

Yes

Go to the next step.

No

Repair or replace the malfunctioning location and perform the repair completion verification.

(See ELECTRONICALLY CONTROLLED BRAKE UNIT REMOVAL/INSTALLATION [R.H.D.].)

(See ELECTRONICALLY CONTROLLED BRAKE UNIT REMOVAL/INSTALLATION [L.H.D.].)

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 work of depressing the brake pedal for 3 s or more and then releasing it for 5 times or more with the ignition switched ON (engine off or on).

•  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 BRAKE FLUID LEVEL • Inspect the brake fluid level. (See BRAKE FLUID INSPECTION [(E)].) • Is the brake fluid level normal?	Yes	Go to the next step.
1		No	Add genuine brake fluid and go to the next step.
2	INSPECT BRAKE PIPE AND BRAKE HOSE FOR BRAKE FLUID LEAKAGE • Perform the brake fluid leakage inspection for the brake pipe and brake hose. • Is there brake fluid leakage?	Yes	Repair or replace the malfunctioning location and perform the repair completion verification. (See FRONT BRAKE HOSE REMOVAL/INSTALLATION [(E)].) (See REAR BRAKE HOSE REMOVAL/INSTALLATION [(E)].)
2		No	Go to the next step.
3	INSPECT ELECTRONICALLY CONTROLLED BRAKE UNIT FOR BRAKE FLUID LEAKAGE • Remove the brake pedal and inspect the electronically controlled brake unit for brake fluid leakage. • Is there brake fluid leakage?	Yes	Repair or replace the malfunctioning location and perform the repair completion verification 2. (See ELECTRONICALLY CONTROLLED BRAKE UNIT REMOVAL/INSTALLATION [R.H.D.].) (See ELECTRONICALLY CONTROLLED BRAKE UNIT REMOVAL/INSTALLATION [L.H.D.].)
3		No	Go to the next step.
4	VERIFY IF AIR IS TRAPPED IN BRAKE LINE • Select the following items from the initialization screen of the M-MDS. 1. “Toolbox” 2. “Work Support” 3. “BRAKES” 4. “Self-Diagnosing Brake Line” • Perform the Self-Diagnosing Brake Line according to the directions on the screen. • Is the result normal?	Yes	Go to the next step.
4		No	Bleed the air from the brake fluid according to the diagnostic result, and go to the repair completion verification. (See BRAKE FLUID AIR BLEEDING [(E)].)
5	INSPECT BRAKE FLUID LEVEL SENSOR SIGNAL CIRCUITS FOR SHORT CIRCUIT • Inspect the applicable circuits for short circuit. (See CIRCUIT INSPECTION.) • Is the circuit normal?	Yes	Go to the next step.
5		No	Repair or replace the malfunctioning location and perform the repair completion verification.
6	INSPECT BRAKE FLUID LEVEL SENSOR FOR MALFUNCTION • Inspect the applicable part. (See BRAKE FLUID LEVEL SENSOR INSPECTION [(E)].) • Is the part normal?	Yes	Go to the next step.
6		No	Repair or replace the malfunctioning location and perform the repair completion verification. (See ELECTRONICALLY CONTROLLED BRAKE UNIT REMOVAL/INSTALLATION [R.H.D.].) (See ELECTRONICALLY CONTROLLED BRAKE UNIT REMOVAL/INSTALLATION [L.H.D.].)
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 work of depressing the brake pedal for 3 s or more and then releasing it for 5 times or more with the ignition switched ON (engine off or on). • 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.