LKA/LDA SYSTEM, Diagnostic DTC:C1A74

DTC Code DTC Name
C1A74 Steering Vibrator System Malfunction

DESCRIPTION

If the forward recognition camera receives a steering vibration ECU malfunction signal, DTC C1A74 is stored.

DTC No. Detection Item DTC Detection Condition Trouble Area
C1A74 Steering Vibrator System Malfunction

When all of the following conditions are met:


  • The vehicle speed is 5 km/h (4 mph) or more.

  • The LKA/LDA system is on.

  • A malfunction signal from the steering vibration ECU (steering wheel assembly) is detected by the forward recognition camera for 5 seconds or more.

  • Forward recognition camera

  • Steering vibration ECU (Steering wheel assembly)

  • Spiral cable sub-assembly

  • Wire harness or connector

WIRING DIAGRAM

A01VWNVE11

CAUTION / NOTICE / HINT

Note


  • Inspect the fuses for circuits related to this system before performing the following procedure.

  • When replacing the forward recognition camera, always replace it with a new one. If a forward recognition camera which was installed to another vehicle is used, the information stored in the forward recognition camera will not match the information from the vehicle. As a result, a DTC may be stored.

  • If the forward recognition camera has been replaced with a new one, be sure to perform Forward Recognition Camera Learning.

    Click here

PROCEDURE


  1. INSPECT STEERING VIBRATION ECU (IG VOLTAGE)


    1. Disconnect the z11 spiral cable sub-assembly connector.

    2. Turn the engine switch on (IG).

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      z11-4 (BHT) (spiral cable sub-assembly side) - Body ground Engine switch on (IG) 11 to 14 V

    4. Turn the engine switch off.

    5. Connect the z11 spiral cable sub-assembly connector.

      Result
      Proceed to
      OK
      NG

    NG

    CHECK HARNESS AND CONNECTOR (STEERING VIBRATOR ECU POWER SOURCE CIRCUIT) Click here

    OK

  2. CHECK HARNESS AND CONNECTOR (SPIRAL CABLE SUB-ASSEMBLY - BODY GROUND)


    1. Disconnect the z11 spiral cable sub-assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      z11-1 (EHT) (spiral cable sub-assembly side) - Body ground Always Below 1 Ω

    3. Connect the z11 spiral cable sub-assembly connector.

      Result
      Proceed to
      OK
      NG

    NG

    CHECK HARNESS AND CONNECTOR (SPIRAL CABLE SUB-ASSEMBLY - BODY GROUND) Click here

    OK

  3. REPLACE STEERING VIBRATOR ECU (STEERING WHEEL ASSEMBLY)


    1. Replace the steering vibration ECU (steering wheel assembly).

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  4. CHECK FOR DTCs (LKA/LDA SYSTEM)


    1. Clear the DTCs.

      Click here


      Chassis > LKA/LDA > Clear DTCs

    2. Perform the following procedure.

      Tech Tips

      If the following procedure is not performed, the previously output DTC cannot be detected.


      1. Turn the engine switch on (IG).

      2. Turn the LKA/LDA system ON.

      3. Drive the vehicle at a speed of 5 km/h (4 mph) or more for 5 seconds or more.

    3. Check for DTCs.

      Click here


      Chassis > LKA/LDA > Trouble Codes
      Result
      Result Proceed to
      DTC C1A74 is not output A
      DTC C1A74 is output B

    A

    END (STEERING VIBRATOR ECU WAS DEFECTIVE)

    B

    REPLACE FORWARD RECOGNITION CAMERA Click here

  5. CHECK HARNESS AND CONNECTOR (SPIRAL CABLE SUB-ASSEMBLY - BODY GROUND)


    1. Disconnect the J23 spiral cable sub-assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      J23-2 (EHT) (connector side) - Body ground Always Below 1 Ω

    3. Connect the J23 spiral cable sub-assembly connector.

      Result
      Proceed to
      OK
      NG

    OK

    REPLACE SPIRAL CABLE SUB-ASSEMBLY Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (SPIRAL CABLE SUB-ASSEMBLY - BODY GROUND)

  6. CHECK HARNESS AND CONNECTOR (STEERING VIBRATOR ECU POWER SOURCE CIRCUIT)


    1. Disconnect the J23 spiral cable sub-assembly connector.

    2. Turn the engine switch on (IG).

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      J23-4 (BHT) (connector side) - Body ground Engine switch on (IG) 11 to 14 V

    4. Turn the engine switch off.

    5. Connect the J23 spiral cable sub-assembly connector.

      Result
      Proceed to
      OK
      NG

    OK

    REPLACE SPIRAL CABLE SUB-ASSEMBLY Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (STEERING VIBRATOR ECU POWER SOURCE CIRCUIT)