ABS Warning Light Remains ON

BRAKE CONTROL: VEHICLE STABILITY CONTROL SYSTEM: ABS Warning Light Remains ON

ABS Warning Light Remains ON

DESCRIPTION

If any of the following is detected, the ABS warning light remains ON.
1. The skid control ECU connectors are disconnected from the skid control ECU.
2. There is a malfunction in the skid control ECU internal circuit.
3. There is an open in the harness between the combination meter and skid control ECU.

HINT: Use of Techstream may not be possible when there is a malfunction in the skid control ECU.

WIRING DIAGRAM









INSPECTION PROCEDURE

NOTE: When replacing the master cylinder solenoid, perform zero point calibration (Programming and Relearning).

PROCEDURE

1. CHECK DTC
(a) Check if DTCs for ABS are recorded.





B -- REPAIR CIRCUITS INDICATED BY OUTPUT DTCS
A -- Continue to next step.
2. INSPECT SKID CONTROL ECU CONNECTOR
(a) Check that the ECU connector is securely connected.
OK:
The connector is securely connected.
NG -- CONNECT CONNECTOR CORRECTLY
OK -- Continue to next step.
3. INSPECT SKID CONTROL ECU (IG1 TERMINAL VOLTAGE)
(a) Connect Techstream to the DLC3.
(b) Start the engine.
(c) Turn Techstream ON.
(d) Select the Data List mode on Techstream.
(e) Measure the voltage output from the ECU displayed on Techstream.

ABS/VSC/TRAC





C -- REPAIR OR REPLACE HARNESS OR CONNECTOR
B -- CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - COMBINATION METER)
A -- Continue to next step.
4. INSPECT REAR DIFFERENTIAL LOCK SWITCH





(a) Remove the rear diff. lock switch.
(b) Disconnect the rear diff. lock switch connector.
(c) Measure the resistance.
Standard:





(d) Reinstall the rear diff. lock switch.
(e) Reconnect the rear diff. lock switch connector.
NG -- REPLACE REAR DIFFERENTIAL LOCK SWITCH
OK -- Continue to next step.
5. CHECK HARNESS AND CONNECTOR (4WD CONTROL ECU - REAR DIFFERENTIAL LOCK SWITCH)





(a) Disconnect the 4WD control ECU connector.
(b) Disconnect the rear diff. lock connector.
(c) Measure the resistance.
Standard (4WD):





Standard (2WD):





(d) Reconnect the rear diff. lock connector.
(e) Reconnect the 4WD control ECU connector.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
6. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - COMBINATION METER)





(a) Disconnect the skid control ECU connector.
(b) Disconnect the combination meter connector.
(c) Measure the resistance.
Standard:





(d) Measure the resistance.
Standard:





(e) Reconnect the combination meter connector.
(f) Reconnect the skid control ECU connector.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
7. INSPECT COMBINATION METER ASSEMBLY
(a) Check the combination meter system (Problem Symptoms Table).
OK:
Combination meter is normal.
NG -- REPLACE COMBINATION METER ASSEMBLY
OK -- REPLACE MASTER CYLINDER SOLENOID