VEHICLE STABILITY CONTROL SYSTEM, Diagnostic DTC:C1379

DTC Code DTC Name
C1379 Downhill Assist Control Switch Malfunction (Test Mode DTC)

DESCRIPTION

DTC C1379 is cleared when the downhill assist control switch sends a downhill assist control operation signal or when test mode ends.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

C1379

Downhill Assist Control Switch Malfunction (Test Mode DTC)

Stored only during test mode.

  • Downhill assist control switch

  • Harness or connector

  • Skid control ECU (Brake actuator assembly)

WIRING DIAGRAM

C197333E04

CAUTION / NOTICE / HINT

Note:

When replacing the skid control ECU (brake actuator assembly), perform zero point calibration.

Click here

PROCEDURE

  1. READ VALUE USING GTS (DOWNHILL ASSIST CONTROL SW)

    1. Turn the ignition switch off.

    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. Check the Data List for proper functioning of the downhill assist control switch.

    Chassis > ABS/VSC/TRC > Data List

    Tester Display

    Measurement Item

    Range

    Normal Condition

    Diagnostic Note

    Downhill Assist Control SW

    Downhill assist control switch

    ON or OFF

    OFF: Downhill assist control switch off

    ON: Downhill assist control switch on

    -

    Chassis > ABS/VSC/TRC > Data List

    Tester Display

    Downhill Assist Control SW

    OK

    The GTS displays ON or OFF according to downhill assist control switch operation.

    Result

    Result

    OK

    NG
    NG

    INSPECT DOWNHILL ASSIST CONTROL SWITCHClick here

    OK

  2. CHECK TEST MODE DTC

    1. Perform the downhill assist control switch check in the Test Mode Procedure.

      Click here

      Chassis > ABS/VSC/TRC > Utility

      Tester Display

      Signal Check

      OK

      Test mode DTC C1379 is cleared.

      Result

      Result

      OK

      NG
    OK

    USE SIMULATION METHOD TO CHECK

    Click hereClick hereClick hereClick here

    NG

    REPLACE BRAKE ACTUATOR ASSEMBLY

    Click here

  3. INSPECT DOWNHILL ASSIST CONTROL SWITCH

    1. Remove the downhill assist control switch.

      Click here

    2. Inspect the downhill assist control switch.

      Click here

      Result

      Result

      OK

      NG
    NG

    REPLACE DOWNHILL ASSIST CONTROL SWITCH

    Click here

    OK

  4. CHECK HARNESS AND CONNECTOR (BRAKE ACTUATOR ASSEMBLY - DOWNHILL ASSIST CONTROL SWITCH)

    1. Disconnect the A64 skid control ECU (brake actuator assembly) connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      A64-29 (HDCS) - G29-4

      Always

      Below 1 Ω

      A64-29 (HDCS) or G29-4 - Body ground

      Always

      10 kΩ or higher

      G29-1 - Body ground

      Always

      Below 1 Ω

      Result

      Result

      OK

      NG
    OK

    REPLACE BRAKE ACTUATOR ASSEMBLY

    Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR