DYNAMIC RADAR CRUISE CONTROL SYSTEM, Diagnostic DTC:C1A4A

DTC Code DTC Name
C1A4A Skid Control Buzzer Circuit

DESCRIPTION

A buzzer sounds to alert the driver when the vehicle-to-vehicle distance becomes less than the set value.

DTC No. DTC Detection Condition Trouble Area
C1A4A When the power switch is on (IG), a skid control buzzer assembly circuit malfunction signal is received from the millimeter wave radar sensor assembly for 3 seconds or more.

  • Skid control buzzer assembly

  • Skid control buzzer circuit

  • Millimeter wave radar sensor assembly

  • Driving support ECU assembly

WIRING DIAGRAM

A01I2O9E05

INSPECTION PROCEDURE

Note


  • When the millimeter wave radar sensor assembly is replaced with a new one, adjustment of the radar sensor beam axis must be performed Click here.

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

PROCEDURE


  1. PERFORM ACTIVE TEST USING TECHSTREAM (RADAR CRUISE APPROACH ALARM BUZZER)


    1. Connect the Techstream to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the Techstream on.

    4. Enter the following menus: Body Electrical / Pre-Collision 2 / Active Test.

    5. Perform Active Test according to the display on the Techstream.

      Pre-Collision 2
      Tester Display Test Part Control Range Diagnostic Note
      Radar Cruise Approach Alarm Buzzer Skid control buzzer assembly ON or OFF Buzzer can be heard
      Result
      Result Proceed to
      Skid control buzzer assembly does not sound A
      Skid control buzzer assembly sounds B

    B

    REPLACE DRIVING SUPPORT ECU ASSEMBLY Click here

    A

  2. INSPECT SKID CONTROL BUZZER ASSEMBLY


    1. Remove the skid control buzzer assembly Click here.

    2. Inspect the skid control buzzer assembly Click here.


    NG

    REPLACE SKID CONTROL BUZZER ASSEMBLY Click here

    OK

  3. CHECK HARNESS AND CONNECTOR (POWER SOURCE)


    1. A01I4EWE09

      Disconnect the I184 skid control buzzer assembly connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      I184-2 (IG1) - Body ground Power switch on (IG) 11 to 14 V
      I184-2 (IG1) - Body ground Power switch off Below 1 V
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Skid Control Buzzer Assembly)

    3. Turn the power switch OFF.

    4. Reconnect the I184 skid control buzzer assembly connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK HARNESS AND CONNECTOR (SKID CONTROL BUZZER ASSEMBLY - MILLIMETER WAVE RADAR SENSOR ASSEMBLY)


    1. Disconnect the I184 skid control buzzer assembly connector.

    2. Disconnect the A86 millimeter wave radar sensor assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      I184-1 (BZ) - A86-10 (BZ) Always Below 1 Ω
      I184-1 (BZ) or A86-10 (BZ) - Body ground Always 10 kΩ or higher

    4. Reconnect the A86 millimeter wave radar sensor assembly connector.

    5. Reconnect the I184 skid control buzzer assembly connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY


    1. Replace the millimeter wave radar sensor assembly Click here.


    NEXT

  6. CHECK FOR DTCs (DTC C1A4A)


    1. Connect the Techstream to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the Techstream on.

    4. Clear the DTCs Click here.

    5. Perform the following to make sure that the DTC detection conditions are met.

      Tech Tips

      If the detection conditions are not met, the malfunction cannot be detected.


      1. Drive the vehicle at a speed for which cruise control operation is possible.

      2. Turn the cruise control main switch (ON-OFF button).

      3. Push the cruise control main switch to -/SET to begin control of vehicle speed using the cruise control system.

    6. Enter the following menus: Powertrain / Radar Cruise / Trouble Codes.

    7. Check for DTCs.

      Result
      Result Proceed to
      DTC C1A4A is not output A
      DTC C1A4A is output B

    B

    REPLACE DRIVING SUPPORT ECU ASSEMBLY Click here

    A

    END (MILLIMETER WAVE RADAR SENSOR ASSEMBLY WAS DEFECTIVE)