35C-HYDRAULIC UNIT CHECK

HYDRAULIC UNIT CHECK

Required Special Tools:

MB991958: Scan tool Sub Assembly

MB991824: Vehicle Communication Interface (V.C.I.)
MB991827: Scan tool USB Cable
MB991910: Scan tool Main Harness A (Vehicles with CAN communication system)

1. Raise the vehicle using a jack and support the specified points with a rigid rack.

caution

Before connecting or disconnecting scan tool, always turn the ignition switch to the LOCK (OFF) position.

Before setting scan tool, turn the ignition key to the LOCK (OFF) position.

3. Confirm that the selector lever is in the "N" position, and then start the engine.

4. When carrying out the actuator tests No.01 to 04, perform the actuator tests using scan tool while depressing the brake pedal. When carrying out the actuator tests No.05 to 08, perform the actuator tests using scan tool without depressing the brake pedal. When carrying out the actuator tests, rotate the wheel by hands to confirm that the braking force changes.

note

While performing the actuator test, the ABS warning light flashes at a rate of 2 Hz.
When ASC-ECU is disabled due to the fail-safe function, the scan tool actuator test cannot be performed.
After the actuator test has been performed, the ABS warning light, brake waning light, ASC ON indicator light, and ASC OFF indicator light illuminate until the ignition switch is turned to ON again or the communication between scan tool and ASC-ECU is terminated.

This is indicated as shown in the above.

6. When any malfunction has been found, take a necessary action according to the "Judgment Table."

Judgment Table

Display on scan tool	Operation	Test result	Judgment	Cause	Measure
01 FR wheel ABS drive 02 FL wheel ABS drive 03 RR wheel ABS drive 04 RL wheel ABS drive	Depress the brake pedal to lock the wheel. Select the vehicle to be inspected using scan tool, perform the actuator test. Rotate the selected wheel by hands to confirm the braking force.	Braking force decreases for 3 seconds from the lock status.	Normal	-	-
		The wheel does not lock even if the brake pedal is depressed.	Error	Clogged brake line other than hydraulic unit	Check and clean the brake line.
				Clogged hydraulic circuit in the hydraulic unit	Replace the hydraulic unit assembly.
		Braking force does not decrease.		Faulty routing of hydraulic unit brake tube	Route the brake tube correctly.
		Braking force does not decrease.		Malfunction of hydraulic unit solenoid valve operation	Replace the hydraulic unit assembly.
05 FR wheel TCL drive 06 FL wheel TCL drive 07 RR wheel TCL drive 08 RL wheel TCL drive	Select the vehicle to be inspected using scan tool, perform the actuator test. Rotate the selected wheel by hands to confirm the braking force.	Lock condition occurs for 3 seconds from the status without braking force.	Normal	-	-
		The wheel does not lock.	Error	Faulty routing of hydraulic unit brake tube Clogged brake line other than hydraulic unit	Check and clean the brake line.
		The wheel does not lock.	Error	Clogged hydraulic circuit in the hydraulic unit	Replace the hydraulic unit assembly.

7. After the inspection, turn the ignition switch to the LOCK (OFF) position, and then disconnect scan tool.

HYDRAULIC UNIT INSTALLATION ADJUSTMENT

Refer to

1. Operate the pre-removal steps for the hydraulic unit.

2. Remove all brake tubes.

3. Remove the protector.

4. Loosen the mounting bolt and nut of the hydraulic unit bracket.

5. Install all brake tubes temporarily.

6. Shake hydraulic unit to all directions with both hands to make the hydraulic unit bracket insulator fit with the unit.

7. Install the hydraulic unit bracket with mounting bolt and nut not to load the brake tube.

8. Install the protector.

9. Install all brake tubes securely.

note	Install the flare nut taking care not to let the brake tube turn together.

10. Operate the post-installation steps of the hydraulic unit.