Hydraulic Control Assembly - Antilock Brakes: Testing and Inspection
ABS HYDRAULIC UNIT INSPECTIONSystem Inspection
1. Verify that the battery is fully charged. With the ignition switch at ON, verify that the ABS warning light goes out after 2 - 4 seconds.
2. If the light stays ON after 2 - 4 seconds the control module detects a failure and will not activate the hydraulic unit. Follow the troubleshooting procedures.
3. Turn the ignition switch to OFF.
4. On level ground, jack up the vehicle and support it evenly on safety stands. Shift the transaxle to neutral or N range.
5. Release the parking brake.
6. Rotate the wheels by hand, and inspect for brake drag.
CAUTION:
^ Connecting the wrong terminals may possibly cause a malfunction. Carefully connect the specified terminals only.
7. Using a jumper wire, connect the 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 the 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.
12. The following are not inspected with the above steps.
- Input system and harness of ABS control module
- Intermittent failure
- Fluid leakage
13. Replace the ABS hydraulic unit as 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 1 L terminal of the control module connector and ground.
Resistance: 1 ohms max.
3. If not as specified, inspect the wiring harness between the ABS motor and the control module, and inspect 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.
Resistance: 1 ohms max.
4. Verify that the motor operates when applying 12 Volts to the connector (2-pin).
5. If not as specified, repair the harness or replace the ABS hydraulic unit as necessary.
Solenoid Valve Inspection (including the Harness of ABS Control Module)
1. Turn the ignition switch to OFF.
2. Measure the resistance between a ground and the illustrated terminals at the ABS control module connector.
Resistance: approx. 3 - 5 ohms
3. If not as specified, inspect the wiring harness between the ABS hydraulic unit connector (8-pin) and the ABS control module, and inspect the solenoid valves.
Solenoid Valve Inspection
1. Disconnect the ABS hydraulic unit connector (8-pin).
2. Measure the resistance between the following terminals. A - E, B - F, C - G, D - H
Resistance: Approx. 3 - 5 ohms
3. If not as specified, repair the hydraulic unit harness or replace the ABS hydraulic unit as necessary.