Hydraulic Control Assembly - Antilock Brakes: Testing and Inspection
Required Special Tool:- MB991502: Scan Tool
CAUTION:
^ The roller of the braking force tester and the tire should be dry during testing.
^ When testing the front brakes, apply the parking brake. When testing the rear brakes, stop the front wheels with chocks.
1. Jack up the vehicle. Then support the vehicle with rigid racks at the specified jack-up points or place the front or rear wheels on the rollers of the braking force tester.
2. Release the parking brake, and feel the drag force (drag torque) on each road wheel. When using the braking force tester, take a reading of the brake drag force.
CAUTION: To prevent damage to scan tool MB991502, always turn the ignition switch to the "LOOK" (OFF) position.
3. Turn the ignition switch to the "LOCK" (OFF) position and set scan tool MB1502 as shown in the illustration.
4. After checking that the shift lever
5. Use scan tool MB991502 to force-drive the actuator.
NOTE:
NOTE: When the ABS has been interrupted by the fail-safe function, scan tool MB991502 actuator testing cannot be used.
6. Turn the wheel by hand and check the change in braking force when the brake pedal is depressed. When using the braking force tester, depress the brake pedal until the braking force is at the following values, and check that the braking force changes to the brake drag force ins
Front wheel: 85 - 981 N (176 - 220 lb.)
Rear wheel: 588 - 784 N (132 - 176 lb.)
The result should be as shown in the diagram above.
7. If the result of inspection is abnormal, repair according to the Diagnosis Table below.
8. After inspection, disconnect the scan tool immediately after turning the ignition switch to the "LOCK" (OFF) position.
DISCHARGED BATTERY
The ABS system consumes a large amount of battery current for its self-check function. If the battery is completely discharged and booster cables are used to start the engine, the engine must be allowed to idle for a few minutes to recharge. If the battery does not recharge, the engine may misfire or stall.
To prevent this condition,
- allow the engine to idle for a few minutes before driving the vehicle, or
- temporarily disable the ABS system by removing the fusible link for the ABS circuit. The ABS warning light will illuminate when the ABS fusible link is removed. After the battery is recharged, reinstall the ABS fusible link and check that the ABS warning light is not illuminated.