LANE DEPARTURE ALERT SYSTEM(w/ Steering Control), 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 lane departure alert system (w/ steering control) is on.

  • The lane departure alert is set to steering vibrator.

  • 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

B002KKCE01

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 adjustment.

    Click here

PROCEDURE


  1. INSPECT STEERING VIBRATION ECU (IG VOLTAGE)


    1. Disconnect the z15 spiral cable sub-assembly connector.

    2. Turn the power switch on (IG).

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      z15-4 (BHT) (spiral cable sub-assembly side) - Body ground Power switch on (IG) 11 to 14 V

    4. Turn the power switch off.

    5. Connect the z15 spiral cable sub-assembly connector.

      Result
      Proceed to
      OK
      NG

    NG

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

    OK

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


    1. Disconnect the z15 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
      z15-1 (EHT) (spiral cable sub-assembly side) - Body ground Always Below 1 Ω

    3. Connect the z15 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 VIBRATION ECU (STEERING WHEEL ASSEMBLY)


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

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  4. CHECK FOR DTCs


    1. Clear the DTCs.

      Click here


      Chassis > LKA/LDA > Clear DTCs

    2. Perform the following procedure.

      Tech Tips

      If the conditions are not met, the system cannot detect the malfunction.

    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 VIBRATION ECU WAS DEFECTIVE)

    B

    REPLACE FORWARD RECOGNITION CAMERA Click here

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


    1. Disconnect the I157 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
      I157-2 (EHT) (connector side) - Body ground Always Below 1 Ω

    3. Connect the I157 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 VIBRATION ECU POWER SOURCE CIRCUIT)


    1. Disconnect the I157 spiral cable sub-assembly connector.

    2. Turn the power switch on (IG).

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      I157-4 (BHT) (connector side) - Body ground Power switch on (IG) 11 to 14 V

    4. Turn the power switch off.

    5. Connect the I157 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 VIBRATION ECU POWER SOURCE CIRCUIT)