ABS Warning Light Remains ON

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

ABS Warning Light Remains ON

DESCRIPTION

The skid control ECU sends the indicator signals to the combination meter assembly via the CAN communication system.
If any of the following is detected, the ABS warning light remains on.

- The skid control ECU connectors are disconnected from the skid control ECU.
- There is a malfunction in the skid control ECU internal circuit.
- There is an open in the wire harness between the combination meter and the skid control ECU.
- The ABS and/or EBD is defective.
HINT: Techstream may not be used when the skid control ECU is abnormal.

WIRING DIAGRAM





INSPECTION PROCEDURE
HINT: Check the condition of each related circuit before troubleshooting Electronic Circuit Inspection Procedure.

PROCEDURE

1. INSPECT CAN COMMUNICATION SYSTEM
(a) Check if a CAN communication system DTC is output ABS (Antilock Brake System).
Result:






B -- INSPECT CAN COMMUNICATION SYSTEM
A -- Continue to next step.
2. CHECK SKID CONTROL ECU CONNECTOR SECURELY CONNECTED
(a) Check if the skid control ECU connector is connected.
OK:
The connector is securely connected.
NG -- CONNECT CONNECTOR TO ECU CORRECTLY
OK -- Continue to next step.
3. CHECK BATTERY
(a) Check the battery voltage.
Standard voltage:
11 to 14 V
NG -- INSPECT CHARGING SYSTEM
OK -- Continue to next step.
4. INSPECT SKID CONTROL ECU CONNECTOR (IG1 TERMINAL VOLTAGE)




(a) Disconnect the skid control ECU connector.
(b) Turn the ignition switch on (IG).
(c) Measure the voltage according to the value(s) in the table below.
Standard voltage:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (IG1 CIRCUIT)
OK -- Continue to next step.
5. INSPECT SKID CONTROL ECU CONNECTOR (GND TERMINAL CONTINUITY)




(a) Measure the resistance according to the value(s) in the table below.
Standard resistance:





(b) Connect the connector.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (GND CIRCUIT)
OK -- Continue to next step.
6. INSPECT COMBINATION METER ASSEMBLY
(a) Connect Techstream to the DLC3.
(b) Select the "Active Test" on Techstream Data List / Active Test.

Active Test: ABS / VSC / TRAC





(c) Check the ABS warning light operation.
OK:
The ABS warning light turns on or off in accordance with Techstream.
Result:






C -- REPLACE COMBINATION METER ASSEMBLY
B -- PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
A -- REPLACE BRAKE ACTUATOR ASSEMBLY