ABS Warning Light Remains ON

BRAKE CONTROL: ELECTRONICALLY CONTROLLED BRAKE SYSTEM: ABS Warning Light Remains ON

ABS Warning Light Remains ON

DESCRIPTION

The skid control ECU is connected to the combination meter via CAN communication.
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 harness between the combination meter and the skid control ECU.
HINT: In some cases, Techstream cannot be used when the skid control ECU is abnormal.

WIRING DIAGRAM





INSPECTION PROCEDURE
NOTICE: When replacing the skid control ECU, perform initialization of linear solenoid valve and calibration Initialization.

PROCEDURE

1. CHECK CAN COMMUNICATION SYSTEM
(a) Check if the CAN communication system DTC is output Diagnosis System.
Result:






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




(a) Disconnect the skid control ECU connector.
(b) Turn the power 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 (GND TERMINAL)




(a) Turn the power switch off.
(b) Disconnect the skid control ECU connectors.
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (GND CIRCUIT)
OK -- Continue to next step.
6. INSPECT COMBINATION METER ASSEMBLY
(a) Reconnect the skid control ECU connectors.
(b) Perform Active Test of the combination meter (meter CPU) using Techstream Scan Tool Testing and Procedures.
OK:
The ABS warning light turns on or off in accordance with Techstream.
HINT: If troubleshooting has been carried out according to the Problem Symptoms Table, refer back to the table and proceed to the next step before replacing the part Problem Symptoms Table.

NG -- REPLACE COMBINATION METER ASSEMBLY
OK -- REPLACE SKID CONTROL ECU