ABS HU/CM SYSTEM INSPECTION

id041300805100

ABS Hydraulic Unit Inspection (On Vehicle)

Preparation

1. Verify that the battery is fully charged.

2. Turn the ignition switch to the ON position, and verify that the ABS warning light goes out after approx. 3.0 s.

3. Turn the ignition switch off.

4. Jack up the vehicle and support it evenly on safety stands.

5. Shift the transaxle to N position.

6. Release the parking brake.

7. Verify that all four wheels rotate.

8. Rotate the wheels by hand, and inspect for brake drag.

• If there is any brake drag, perform regular brake inspection.
• If there no brake drag, perform ABS HU/CM operation inspection.

Operation inspection

1. Perform "Preparation".

2. Connect the WDS or equivalent to the DLC-2.

3. Set up an active command mode inspection according to the combination of commands below.

Operation state

Command name

Command

Transmission type

PMP_MOTOR

RF_OUTLET

RF_INLET

Brake pressure retention
Off
Off
On
Manual
Brake pressure reduction
On
On
On

The chart above shows an example of a right front wheel inspection.

Note
• When working with two people, one should press on the brake pedal, the other should attempt to rotate the wheel being inspected.

4. Send the command while pressing on the brake pedal and attempting to rotate the wheel being inspected.

5. When pressure is being maintained, and a clicking sound indicating the solenoid is operating comes from the ABS HU/CM, confirm that the wheel does not rotate. When pressure is being reduced, and a clicking sound indicating the solenoid is operating comes from the ABS HU/CM, confirm that the wheel rotates.

• By performing the above inspection, the following operating conditions can be verified.
- The ABS HU/CM brake lines are normal.
- The ABS HU/CM hydraulic system is not significantly abnormal (including inside ABS HU/CM).
- The ABS HU/CM internal electrical parts (solenoid, motor and other parts) are normal.
- The ABS HU/CM output system wiring harnesses (solenoid valve, relay system) are normal.
• However, the following items cannot be checked.
- The ABS HU/CM input system wiring harnesses and parts are abnormal.
- Extremely small leaks in the ABS HU/CM internal hydraulic system.
- Unusual intermittent occurrences in the above items.