ABS Warning Light Circuit (Remains ON)

BRAKE CONTROL: ANTI-LOCK BRAKE SYSTEM: ABS Warning Light Remains ON

ABS Warning Light Remains ON

CAUTION / NOTICE / HINT

When reading DTCs by SST (check wire), if the ABS warning light remains on, troubleshoot by following the inspection procedure.

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 or short in the wire harness between the combination meter and skid control ECU.
HINT: The intelligent tester may not be usable when there is a malfunction in the skid control ECU.

WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. CHECK DTC
(a) Is DTC output for ABS?
Result:






B -- REPAIR CIRCUIT INDICATED BY OUTPUT CODE
A -- Continue to next step.
2. INSPECT SKID CONTROL ECU CONNECTOR
(a) Check the ECU connector's connecting condition.
OK:
The connector should be securely connected.
NG -- CONNECT CONNECTOR TO ECU
OK -- Continue to next step.
3. CHECK SKID CONTROL ECU (IG1 VOLTAGE)
(a) WHEN USING INTELLIGENT TESTER:
(1) Connect the intelligent tester to the DTC3.
(2) Start the engine.
(3) Select the tester menus: DIAGNOSTIC, OBD/MOBD, ABS/VSC and DATA LIST.
(4) Read the IG VOLTAGE status.






OK:
The tester displays Normal (IG VOLTAGE of the ABS ECU is 9.8 to 14 V).





(b) WHEN NOT USING INTELLIGENT TESTER:
(1) Disconnect the S1 skid control ECU connector.
(2) Turn the ignition switch to the ON position.
(3) Measure the voltage of the wire harness side connector.
Standard voltage:






NG -- REPAIR OR REPLACE HARNESS AND CONNECTOR
OK -- Continue to next step.
4. CHECK WIRE HARNESS (SKID CONTROL ECU - COMBINATION METER)





(a) Disconnect the S1 skid control ECU connector.
(b) Disconnect the C6 combination meter connector.
(c) Measure the resistance of the wire harness side connectors.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS AND CONNECTOR
OK -- Continue to next step.
5. CHECK WIRE HARNESS (SKID CONTROL ECU - BODY GROUND)





(a) Disconnect the S1 skid control ECU connector.
(b) Measure the resistance of the wire harness side connector.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS AND CONNECTOR
OK -- Continue to next step.
6. INSPECT COMBINATION METER ASSEMBLY
(a) Check combination meter assembly Problem Symptoms Table.
NG -- CHECK COMBINATION METER ASSEMBLY
OK -- REPLACE BRAKE ACTUATOR ASSEMBLY