ANTI-LOCK BRAKE SYSTEM ABS Warning Light Remains ON

DESCRIPTION

The skid control ECU (brake actuator assembly) is connected to the combination meter assembly via CAN communication.

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 (brake actuator assembly).

• 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 the skid control ECU (brake actuator assembly).

• The ABS control system is defective.

• w/ Rear Differential Lock:

  The rear differential is locked.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

PROCEDURE

1. CHECK CAN COMMUNICATION SYSTEM

   
   

   1. Check if CAN communication system DTCs are output.

      for LHD: Click here

      for RHD: Click here

      Result
      Proceed to DTC is not output DTC is output

   
   

   DTC is output

   CHECK CAN COMMUNICATION SYSTEM for LHD: Click here CHECK CAN COMMUNICATION SYSTEM for RHD: Click here

   DTC is not output

2. CHECK IF BRAKE ACTUATOR ASSEMBLY CONNECTOR IS SECURELY CONNECTED

   
   

   1. Check if the skid control ECU (brake actuator assembly) connector is securely connected.

      OK
      The connector is securely connected.

      Result
      Proceed to OK NG

   
   

   NG

   CONNECT CONNECTOR TO BRAKE ACTUATOR ASSEMBLY CORRECTLY

   OK

3. INSPECT BATTERY

   
   

   1. Check the battery voltage.

      Standard voltage
      11 to 14 V

      Result
      Proceed to OK NG

   
   

   NG

   CHECK OR REPLACE CHARGING SYSTEM OR BATTERY for 1GR-FE: Click here CHECK OR REPLACE CHARGING SYSTEM OR BATTERY for 1KD-FTV: Click here CHECK OR REPLACE CHARGING SYSTEM OR BATTERY for 2GD-FTV: Click here CHECK OR REPLACE CHARGING SYSTEM OR BATTERY for 2KD-FTV: Click here CHECK OR REPLACE CHARGING SYSTEM OR BATTERY for 2TR-FE: Click here CHECK OR REPLACE CHARGING SYSTEM OR BATTERY for 5L-E: Click here

   OK

4. CHECK TERMINAL VOLTAGE (IG1 TERMINAL)

   
   
   1. 

      *a	Front view of wire harness connector (to Skid Control ECU [Brake Actuator Assembly])

      Disconnect the A68 skid control ECU (brake actuator assembly) connector.

   2. Turn the ignition switch to ON.

   3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Switch Condition Specified Condition A68-34 (IG1) - Body ground Ignition switch ON 11 to 14 V

      Result
      Proceed to OK NG

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR (IG1 CIRCUIT)

   OK

5. CHECK HARNESS AND CONNECTOR (GND1 TERMINAL)

   
   

   1. Turn the ignition switch off.

   2. 

      *a	Front view of wire harness connector (to Skid Control ECU [Brake Actuator Assembly])

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

      Standard Resistance
      Tester Connection Condition Specified Condition A68-1 (GND1) - Body ground Always Below 1 Ω

      Result
      Proceed to OK (w/o Rear Differential Lock) OK (w/ Rear Differential Lock) NG

   
   

   OK (w/o Rear Differential Lock)

   GO TO STEP 7 Click here

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR (GND1 CIRCUIT)

   OK (w/ Rear Differential Lock)

6. CHECK FOR DIFFERENTIAL SYSTEM

   
   

   1. Reconnect the A68 skid control ECU (brake actuator assembly) connector.

   2. Connect the GTS to the DLC3.

   3. Turn the ignition switch to ON.

   4. Turn the GTS on.

   5. Enter the following menus: Powertrain / Four Wheel Drive / Trouble Codes.

   6. Check for DTCs.

      
      Powertrain > Four Wheel Drive > Trouble Codes

      Result
      Proceed to DTCs are not output DTCs are output

   
   

   DTCs are output

   GO TO DIFFERENTIAL SYSTEM (DIAGNOSTIC TROUBLE CODE CHART) Click here

   DTCs are not output

7. READ VALUE USING GTS (ABS WARNING LIGHT)

   
   

   1. Reconnect the A68 skid control ECU (brake actuator assembly) connector.

   2. Connect the GTS to the DLC3.

   3. Turn the ignition switch to ON.

   4. Turn the GTS on.

   5. Enter the following menus: Chassis / ABS/VSC/TRC / Data List.

   6. According to the display on the GTS, read the Data List.

      
      Chassis > ABS/VSC/TRC > Data List

      Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
      ABS Warning Light	ABS warning light	OFF or ON	OFF: Warning light off ON: Warning light on	-

      
      Chassis > ABS/VSC/TRC > Data List

      Tester Display
      ABS Warning Light

   7. Check the GTS display condition of the ABS warning light.

      Result
      Proceed to Display of the Data List remains OFF Display of the Data List remains ON

   
   

   Display of the Data List remains OFF

   INSPECT METER / GAUGE SYSTEM Click here

   Display of the Data List remains ON

   REPLACE BRAKE ACTUATOR ASSEMBLY Click here