VEHICLE STABILITY CONTROL SYSTEM, Diagnostic DTC:C1379

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

DESCRIPTION

w/ Downhill Assist Control:

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

w/ Crawl Control:

DTC C1379 is cleared when the crawl control switch sends a crawl 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.

  • Combination switch

  • Harness or connector

  • Master cylinder solenoid (Skid control ECU)

WIRING DIAGRAM

C214516E10
C215184E07

CAUTION / NOTICE / HINT

Note:

When replacing the master cylinder solenoid, perform calibration (Click here).

PROCEDURE

  1. CONFIRM VEHICLE SPECIFICATIONS

    1. Confirm the vehicle specifications.

      Result

      Result

      Proceed to

      w/ Downhill Assist Control

      A

      w/ Crawl Control

      B
    B

    CHECK CAN BUSClick here

    A

  2. READ VALUE USING INTELLIGENT TESTER (DOWNHILL ASSIST CONTROL SW)

    1. Turn the engine switch off.

    2. Connect the intelligent tester to the DLC3.

    3. Turn the engine switch on (IG).

    4. Turn the intelligent tester 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

      ON: Downhill assist control on

      OFF: Downhill assist control off

      -

      OK

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

      Result

      Result

      OK

      NG
    NG

    INSPECT DOWNHILL ASSIST CONTROL SWITCH (COMBINATION SWITCH)Click here

    OK

  3. CHECK TEST MODE DTC

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

      Click here

      OK

      Test mode DTC C1379 is cleared.

      Result

      Result

      OK

      NG

      Chassis > ABS/VSC/TRC > Utility

      Tester Display

      Test Mode
    OK

    USE SIMULATION METHOD TO CHECK

    Click here

    NG

    REPLACE MASTER CYLINDER SOLENOID

    Click here

  4. INSPECT DOWNHILL ASSIST CONTROL SWITCH (COMBINATION SWITCH)

    1. Remove the combination switch.

      Click here

    2. C219806C01

      *a

      Component without harness connected

      (Downhill Assist Control Switch [Combination Switch])

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

      Standard Resistance

      Tester Connection

      Switch Condition

      Specified Condition

      15 (+B2) - 9 (E)

      Pressed

      Below 1 Ω

      Not pressed

      10 kΩ or higher

      Result

      Result

      OK

      NG
    NG

    REPLACE COMBINATION SWITCH ASSEMBLY

    Click here

    OK

  5. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - DOWNHILL ASSIST CONTROL SWITCH)

    1. Disconnect the A7 skid control ECU connector.

    2. Disconnect the i5 combination switch connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      A7-44 (HDCS) - i5-15 (+B2)

      Always

      Below 1 Ω

      A7-44 (HDCS) - Body ground

      Always

      10 kΩ or higher

      i5-9 (E) - Body ground

      Always

      Below 1 Ω

      Result

      Result

      OK

      NG
    OK

    REPLACE MASTER CYLINDER SOLENOID

    Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  6. CHECK CAN BUS

    1. Check that there are no problems with the CAN communication system.

      Click here

      Result

      Result

      OK

      NG
    NG

    GO TO CAN COMMUNICATION SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING)

    Click here

    OK

  7. READ VALUE USING INTELLIGENT TESTER (CRAWL CONTROL SWITCH)

    1. Turn the engine switch off.

    2. Connect the intelligent tester to the DLC3.

    3. Turn the engine switch on (IG).

    4. Turn the intelligent tester on.

    5. Enter the following menus: Body Electrical / D-SEAT SW / Data List.

    6. Check the Data List for proper functioning of the crawl control switch.

      Body Electrical > D-SEAT SW > Data List

      Tester Display

      Measurement Item

      Range

      Normal Condition

      Diagnostic Note

      Crawl Control Main Switch

      Crawl control switch (ON/OFF switch)

      ON or OFF

      ON: Crawl control on

      OFF: Crawl control off

      -

      Crawl Control Up Switch

      Crawl Control Switch (Speed selector switch)

      ON or OFF

      ON: Speed selector switch pushed to the up side and held

      OFF: Speed selector switch not pushed to the up side

      -

      Crawl Control Down Switch

      Crawl Control Switch (Speed selector switch)

      ON or OFF

      ON: Speed selector switch pushed to the down side and held

      OFF: Speed selector switch down side not pushed to the down side

      -

      OK

      The intelligent tester displays according to crawl control switch operation.

      Result

      Result

      OK

      NG
    NG

    CHECK HARNESS AND CONNECTOR (CRAWL CONTROL SWITCH - DRIVING SUPPORT SWITCH CONTROL ECU)Click here

    OK

  8. CHECK TEST MODE DTC

    1. Perform the crawl control switch check in the Test Mode Procedure.

      Click here

      OK

      Test mode DTC C1379 is cleared.

      Result

      Result

      OK

      NG

      Chassis > ABS/VSC/TRC > Utility

      Tester Display

      Test Mode
    OK

    USE SIMULATION METHOD TO CHECK

    Click here

    NG

    REPLACE MASTER CYLINDER SOLENOID

    Click here

  9. CHECK HARNESS AND CONNECTOR (CRAWL CONTROL SWITCH - DRIVING SUPPORT SWITCH CONTROL ECU)

    1. Disconnect the i5 combination switch connector.

    2. Disconnect the G60 driving support switch control ECU connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      i5-6 (ECU) - G60-15 (SWI3)

      Always

      Below 1 Ω

      i5-6 (ECU) - Body ground

      Always

      10 kΩ or higher

      i5-5 (UP) - G60-13 (SWI4)

      Always

      Below 1 Ω

      i5-5 (UP) - Body ground

      Always

      10 kΩ or higher

      i5-3 (DN) - G60-14 (SWI5)

      Always

      Below 1 Ω

      i5-3 (DN) - Body ground

      Always

      10 kΩ or higher

      i5-9 (E) - Body ground

      Always

      Below 1 Ω

      Result

      Result

      OK

      NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  10. INSPECT CRAWL CONTROL SWITCH (COMBINATION SWITCH)

    1. Remove the combination switch.

      Click here

    2. C220879C01

      *1

      Speed Selector Switch

      *2

      ON/OFF Switch

      *a

      Component without harness connected

      (Crawl Control Switch [Combination Switch])

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

      Standard Resistance

      Tester Connection

      Switch Condition

      Specified Condition

      5 (UP) - 9 (E)

      SPEED (UP): Pressed

      Below 1 Ω

      SPEED (UP): Not Pressed

      10 kΩ or higher

      3 (DN) - 9 (E)

      SPEED (DOWN): Pressed

      Below 1 Ω

      SPEED (DOWN): Not Pressed

      10 kΩ or higher

      6 (ECU) - 9 (E)

      ON/OFF: Pressed

      Below 1 Ω

      ON/OFF: Not pressed

      10 kΩ or higher

      Result

      Result

      OK

      NG
    OK

    REPLACE DRIVING SUPPORT SWITCH CONTROL ECU

    Click here

    NG

    REPLACE COMBINATION SWITCH ASSEMBLY

    Click here