ABS Warning Light Remains ON
BRAKE CONTROL: VEHICLE STABILITY CONTROL SYSTEM (for Vacuum Brake Booster): ABS Warning Light Remains ON
- ABS Warning Light Remains ON
DESCRIPTION
If any of the following is detected, the ABS warning light remains on.
* The skid control ECU (brake actuator assembly) connectors are disconnected from the skid control ECU.
* There is a malfunction in the skid control ECU (brake actuator assembly) internal circuit.
* There is an open in the harness between the combination meter assembly and skid control ECU (brake actuator assembly).
* The anti-lock brake system is defective.
* The voltage at terminal IG1 is high.
* The rear differential is locked.*
* *: w/ Rear Differential Lock
HINT
It may not be possible to use the Techstream when the skid control ECU (brake actuator assembly) is abnormal.
WIRING DIAGRAM
INSPECTION PROCEDURE
NOTICE:
* When replacing the skid control ECU (brake actuator assembly), perform calibration Vehicle Stability Control System (for Vacuum Brake Booster).
* Inspect the fuses for circuits related to this system before performing the following inspection procedure.
PROCEDURE
1. CHECK THAT SKID CONTROL ECU CONNECTOR IS SECURELY CONNECTED
(a) Check the skid control ECU (brake actuator assembly) connector connection.
OK:
The connector is securely connected.
NG -- CONNECT CONNECTOR TO ECU CORRECTLY
OK -- Continue to next step.
2. CHECK DTC
(a) Check for DTCs Vehicle Stability Control System (for Vacuum Brake Booster).
Result
B -- REPAIR CIRCUITS INDICATED BY OUTPUT DTCS Vehicle Stability Control System (for Vacuum Brake Booster)
A -- Continue to next step.
3. INSPECT BATTERY
(a) Inspect the battery voltage.
for 1GR-FE Testing and Inspection
for 2TR-FE Testing and Inspection
Standard Voltage:
11 to 14 V
Result
B -- CHECK CHARGING SYSTEM Testing and Inspection
C -- CHECK CHARGING SYSTEM Testing and Inspection
A -- Continue to next step.
4. CHECK CAN COMMUNICATION LINE
(a) Turn the ignition switch off.
(b) Connect the Techstream to the DLC3.
(c) Turn the ignition switch to ON.
(d) Turn the Techstream on.
(e) Select CAN Bus Check from the System Selection Menu screen and follow the prompts on the screen to inspect the CAN bus Diagnosis System.
OK:
CAN Bus Check indicates no malfunctions in CAN communication.
NG -- GO TO CAN COMMUNICATION SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING) How to Proceed With Troubleshooting
OK -- Continue to next step.
5. PERFORM ACTIVE TEST USING TECHSTREAM (Indicate Lamp ABS)
(a) Turn the ignition switch off.
(b) Connect the Techstream to the DLC3.
(c) Turn the ignition switch to ON.
(d) Turn the Techstream on.
(e) Enter the following menus: Body Electrical / Combination Meter / Active Test.
(f) According to the display on the Techstream, perform the Active Test.
Combination Meter
(g) Check that the ABS warning light on the combination meter assembly turns on or off in accordance with the Techstream operation.
OK:
The ABS Warning Light turns on or off in accordance with the Techstream operation.
NG -- GO TO METER / GAUGE SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING) How To Proceed With Troubleshooting
OK -- Continue to next step.
6. CHECK HARNESS AND CONNECTOR (IG1 TERMINAL)
(a) Disconnect the S1 skid control ECU (brake actuator assembly) connector.
(b) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
Text in Illustration
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
7. CHECK HARNESS AND CONNECTOR (GND TERMINAL)
(a) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Text in Illustration
(b) Reconnect the S1 skid control ECU (brake actuator assembly) connector.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
8. CHECK HARNESS AND CONNECTOR (EXI3 TERMINAL)
(a) w/ Rear Differential Lock
(1) Set the vehicle in the rear differential free state using the differential lock switch.
(2) Disconnect the S1 skid control ECU (brake actuator assembly) connector.
(3) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
Text in Illustration
(4) Reconnect the S1 skid control ECU (brake actuator assembly) connector.
(b) w/o Rear Differential Lock
(1) Disconnect the S1 skid control ECU (brake actuator assembly) connector.
(2) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
Text in Illustration
Result
(3) Reconnect the S1 skid control ECU (brake actuator assembly) connector.
B -- CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU EXI3 CIRCUIT)
C -- REPAIR OR REPLACE HARNESS OR CONNECTOR
A -- REPLACE BRAKE ACTUATOR ASSEMBLY Removal
9. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU EXI3 CIRCUIT)
(a) Disconnect the S1 skid control ECU (brake actuator assembly) connector.
(b) Disconnect the F14 4 wheel drive control ECU connector.
(c) Disconnect the C10 combination meter assembly connector.
(d) Disconnect the T13 differential lock indicator switch connector.
(e) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
10. INSPECT DIFFERENTIAL LOCK INDICATOR SWITCH
(a) Remove the differential lock indicator switch.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Text in Illustration
NG -- REPLACE DIFFERENTIAL LOCK INDICATOR SWITCH
OK -- Continue to next step.
11. REPLACE 4 WHEEL DRIVE CONTROL ECU
(a) Replace the 4 wheel drive control ECU.
(b) Reconnect the S1 skid control ECU (brake actuator assembly) connector.
(c) Turn the ignition switch to ON.
(d) Check that the ABS warning light comes on when the ignition switch is turned to ON, and turns off in approximately 3 seconds.
OK:
ABS warning light turns off.
NG -- REPLACE COMBINATION METER ASSEMBLY Removal
OK -- END