Hydraulic Control Assembly - Antilock Brakes: Testing and Inspection

SYSTEM INSPECTION
1. Verify that the battery is fully charged. Verify that the ABS warning light goes out after the engine is started.
2. If the light stays on after the engine has started, the ABS control module detects a failure and will not activate the hydraulic unit. Follow the troubleshooting procedures.
3. Turn off the engine.
4. On level ground, jack up the vehicle and support it evenly on safety stands. Shift the transaxle to neutral position.
5. Release the parking brake.
6. Rotate the wheels by hand, and inspect for brake drag.

Caution: Misconnecting the data link connector terminals may cause a malfunction. Properly connect the specified terminals only.





7. Using a jumper wire, connect TBS and GND terminals of the data link connector.
8. Depress the brake pedal, and have an assistant, verify that the right front wheel will not turn.
9. With the brake pedal still depressed, turn the ignition switch to ON and verify that the brake is released momentarily (approx. 0.5 sec.) and that the wheel turns when pressure-reduction operates.





10. Inspect operation of the remaining wheels in order: left front, right rear, left rear.
11. If steps 9 and 10 show correct operation, the following systems are okay:
- Brake piping to ABS hydraulic unit
- Braking system, including ABS hydraulic unit
- Electrical system in ABS hydraulic unit (solenoid, ABS motor, etc.)
- ABS control module, its output system (solenoid, relay, etc.) and harness
The following are not checked with the above steps.
- Input system and harness of ABS control module
- Intermittent failure
- Fluid leakage
12. Replace the ABS hydraulic unit if necessary.

ABS MOTOR INSPECTION (INCLUDING HARNESS TO ABS CONTROL MODULE)
1. Turn the ignition switch to OFF, and disconnect the ABS control module connector.





2. Measure the resistance between terminal 1L [1C for ABS/TCS] of the control module connector and a ground.
3. If not as specified, check the wiring harness between the motor and the control module and check the ABS motor.

ABS MOTOR INSPECTION
1. Turn the ignition switch to OFF.
2. Disconnect the ABS hydraulic unit connector (2-pin).





3. Measure the resistance between the connector terminals.
4. Verify that the motor operates when applying 12 V to connector (2-pin).
5. If not as specified, repair harness or replace the ABS hydraulic unit if necessary.

SOLENOID VALVE INSPECTION (INCLUDING HARNESS TO ABS CONTROL MODULE)
1. Turn the ignition switch to OFF.





2. Measure the resistance between a ground and the following terminals at the ABS control module connector.
[]:for ABS/TCS
Terminal 1A [2V]: Right rear
Terminal 1B [2W]: Left front
Terminal 1C [2Y]: Right front
Terminal 1D [2Z]: Left rear
3. If not as specified, check the wiring harness between the ABS hydraulic unit connector (8-pin) and the ABS control module and check the solenoid valves.

SOLENOID VALVE INSPECTION
1. Disconnect the ABS hydraulic unit connector (8-pin).





2. Measure the resistance between A-E, B-F, C-G, and D-H terminals.
3. If not as specified, repair the hydraulic module harness or replace the ABS hydraulic unit if necessary.