ABS Does Not Operate

ABS DOES NOT OPERATE






DETECTING CONDITION






INSPECTION PROCEDURES
DTC INSPECTION
1. Connect the Scan tool with the data link connector and turn the ignition switch ON.
2. Verify that the system is operating to specifications.
Is the system operating to specifications?
NO
> Check the power source circuit.
YES
> Erase the DTC and recheck using Scan tool.

CHECK THE POWER SOURCE CIRCUIT.
1. Disconnect the connector from the ABS control module.
2. Turn the ignition switch ON, measure the voltage between terminal 18 of the ABS control module harness side connector and body ground.

Specification: approximately B+


Is the voltage within specification?
YES
> Check the ground circuit.
NO
> Check the harness or connector between the fuse (10A) in the engine compartment junction block and the ABS control module. Repair if necessary.





CHECK THE GROUND CIRCUIT.
1. Disconnect the connector from the ABS control module.
2. Check for continuity between terminals 1,4 of the ABS control module harness side connector and ground point.
Is there continuity?
YES
> Check the wheel speed sensor circuit.
NO
> Repair an open in the wire and ground point.





CHECK THE WHEEL SPEED SENSOR CIRCUIT.
Refer to the DTC troubleshooting procedures.
Is the system operating to specifications?
> Check the hydraulic circuit for leakage.
> Repair or replace the wheel speed sensor.

CHECK THE HYDRAULIC CIRCUIT FOR LEAKAGE.
Refer to the hydraulic lines.
Inspect leakage of the hydraulic lines.
Is the system operating to specifications?
> The problem is still occurring, replace the ABS control module.
> Replace the leaking hydraulic lines




DETECTING CONDITION






INSPECTION PROCEDURES
DTC INSPECTION
1. Connect the Scan tool with the data link connector and turn the ignition switch ON.
2. Verify that the system is operating to specifications.
Is the system operating to specifications?
NO
> Check the wheel speed sensor circuit.
YES
> Erase the DTC and recheck using Scan tool.

CHECK THE WHEEL SPEED SENSOR CIRCUIT.
Refer to the DTC troubleshooting procedures.
Is the system operating to specifications?
> Check the stop lamp switch circuit.
> Repair or replace the wheel speed sensor.

CHECK THE STOP LAMP SWITCH CIRCUIT.
1. Check that stop lamp lights up when brake pedal is depressed and turns off when brake pedal is released.
2. Measure the voltage between terminal 20 of the ABS control module harness side connector and body ground when brake pedal is depressed.

Specification: approximately B+


Is the voltage within specification?
YES
> Check the hydraulic circuit for leakage.
NO
> Repair the stop lamp switch. Repair an open in the wire between the ABS control module and the stop lamp switch.





CHECK THE HYDRAULIC CIRCUIT FOR LEAKAGE.
Refer to the hydraulic lines.
Inspect leakage of the hydraulic lines.
Is the system operating to specifications?
> The problem is still occurring, replace the ABS control module.
> Replace the leaking hydraulic lines.