ANTI-LOCK BRAKE SYSTEM, Diagnostic DTC:Always ON

DTC Code DTC Name
Always ON Malfunction in ABS ECU

DESCRIPTION

Tech Tips

There is a case that intelligent tester cannot be used when ECU is abnormal.

DTC No. DTC Detecting Condition Trouble Area
Always ON

Either of the following 1. 2. 3. or 4. is detected:


  1. The ECU connectors are OFF from the ECU.

  2. There is a malfunction in the ECU internal circuit.

  3. There is a malfunction in ABS warning light circuit.

  4. IG1 terminal voltage is 18.5 V or more.

  • Battery

  • ABS warning light circuit

  • Charging system

  • Power source circuit

  • Skid Control ECU

WIRING DIAGRAM

A01KIATE01

INSPECTION PROCEDURE

PROCEDURE


  1. INSPECT BATTERY (TERMINAL VOLTAGE)


    1. Check the battery positive voltage.

      OK
      Voltage: 10 - 14 V

    NG

    CHECK AND REPLACE CHARGING SYSTEM

    OK

  2. CHECK SKID CONTROL ECU CONNECTOR SECURELY CONNECTED


    NG

    CONNECT CONNECTORS

    OK

  3. CHECK RECONFIRM DTC


    1. Check DTC on Click here.

      A Malfunction Code
      B Normal Code

    B

    REPAIR CIRCUIT INDICATED BY OUTPUT CODE

    A

  4. CHECK VOLTAGE OF ECU IG POWER SOURCE (IG1 TERMINAL VOLTAGE)

    In case of using the intelligent tester:


    1. Select the DATALIST mode on the intelligent tester.

    2. A01KG3NE01

      Check the voltage condition output from the ECU displayed on the intelligent tester.

      OK
      "Normal" is displayed.

      In case of not using the intelligent tester:

    3. Remove the skid control ECU with connectors still connected.

    4. Turn the ignition switch ON, measure voltage between terminals IG1 and GND of skid control ECU connector.

      OK
      Voltage: 10 - 14 V

    OK

    CHECK HARNESS AND CONNECTOR (DLC3 - SKID CONTROL ECU) Click here

    NG

  5. CHECK HARNESS AND CONNECTOR (BATTERY - SKID CONTROL ECU)


    1. Check for open and short circuit in harness and connector between battery and skid control ECU Click here.


    NG

    CHECK AND REPAIR HARNESS AND CONNECTOR

    OK

  6. CHECK HARNESS AND CONNECTOR (DLC3 - SKID CONTROL ECU)


    1. Check for short circuit in harness and connector between terminal Tc of DLC3 and skid control ECU Click here.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  7. CHECK ABS WARNING LIGHT

    In case of using the intelligent tester:


    1. Select the ACTIVE TEST mode on the intelligent tester.

    2. A01KGXFE01

      Check that "ON" and "OFF" of the ABS warning light can be shown on the combination meter by the intelligent tester.

      In case of not using the intelligent tester:

    3. Turn the ignition switch OFF.

    4. Remove the skid control ECU with connectors still connected.

    5. Using a service wire, connect terminals WA and GND of the skid control ECU harness side connector.

    6. Turn the ignition switch ON.

    7. Check the ABS warning light goes off.


    OK

    CHECK AND REPLACE SKID CONTROL ECU ASSEMBLY

    NG

    CHECK AND REPLACE COMBINATION METER ASSEMBLY