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DYNAMIC RADAR CRUISE CONTROL SYSTEM, Diagnostic DTC:C1A4A

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DTC Code DTC Name
C1A4A Skid Control Buzzer Circuit
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DESCRIPTION

Based on dynamic radar cruise control system operation, the driving support ECU assembly provides warnings to the driver by sending a request signal to the millimeter wave radar sensor assembly to sound the skid control buzzer assembly.

When the millimeter wave radar sensor assembly detects a malfunction in the skid control buzzer assembly circuit, a malfunction signal is sent to the driving support ECU assembly, and this DTC is stored.

DTC No. Detection Item DTC Detection Condition Trouble Area
C1A4A Skid Control Buzzer Circuit When the cruise control switch is on and the vehicle is being driven at a speed of 36 km/h (22 mph) or more, a skid control buzzer assembly circuit malfunction signal is received from the millimeter wave radar sensor assembly for 1 second or more.

  • Harness or connector

  • Skid control buzzer assembly

  • Millimeter wave radar sensor assembly

  • Driving support ECU assembly
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WIRING DIAGRAM

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CAUTION / NOTICE / HINT

Note:

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

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PROCEDURE


  1. Click here

    CHECK FOR DTCs (RADAR CRUISE)


    1. Clear the DTCs.

      Click here


      1. Powertrain > Radar Cruise > Clear DTCs


    2. Make sure that the DTC detection conditions are met.

      Tip:

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

    3. Check for DTCs.

      Click here


      1. Powertrain > Radar Cruise > Trouble Codes


      Result
      Result Proceed to
      DTC C1A4A and U0235 are not output A
      DTC C1A4A and U1104 are not output
      DTC C1A4A is output B
      DTC C1A4A and U0235 are output C
      DTC C1A4A and U1104 are output D

  2. Click here

    PERFORM ACTIVE TEST USING GTS (RADAR CRUISE APPROACH ALARM BUZZER)


    1. Connect the GTS to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the GTS on.

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

    5. Perform "Active Test" according to the display on the GTS.


      1. Body Electrical > Pre-Crash 2 > Active Test
        Tester Display Measurement Item Control Range Diagnostic Note
        Radar Cruise Approach Alarm Buzzer Skid control buzzer assembly ON or OFF Buzzer can be heard



      1. Body Electrical > Pre-Crash 2 > Active Test
        Tester Display
        Radar Cruise Approach Alarm Buzzer




      OK
      Skid control buzzer assembly sounds.
      Note:

      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.

      Result
      Proceed to
      OK
      NG

  3. Click here

    INSPECT SKID CONTROL BUZZER


    1. Remove the skid control buzzer assembly.

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    2. Inspect the skid control buzzer assembly.

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      Result
      Proceed to
      OK
      NG

  4. Click here

    CHECK TERMINAL VOLTAGE (POWER SOURCE OF SKID CONTROL BUZZER ASSEMBLY)


    1. A01VNVYC45
      *a

      Front view of wire harness connector

      (to Skid Control Buzzer Assembly)

      Disconnect the O40 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
      O40-2 (IG1) - Body ground Engine switch on (IG) 11 to 14 V
      O40-2 (IG1) - Body ground Engine switch off Below 1 V
      Result
      Proceed to
      OK
      NG

    • OKClick here
    • NG

      REPAIR OR REPLACE HARNESS OR CONNECTOR (SKID CONTROL BUZZER ASSEMBLY - BATTERY)

  5. Click here

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


    1. Disconnect the O40 skid control buzzer assembly connector.

    2. Disconnect the B7 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
      O40-1 (BZ) - B7-10 (BZ) Always Below 1 Ω
      O40-1 (BZ) or B7-10 (BZ) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    • OKClick here
    • NG

      REPAIR OR REPLACE HARNESS OR CONNECTOR

  6. Click here

    REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY


    1. Replace the millimeter wave radar sensor assembly with a new one.

      Click here

    2. Perform millimeter wave radar sensor assembly adjustment.

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      Result
      Proceed to
      NEXT

  7. Click here

    CHECK FOR DTCs (RADAR CRUISE)


    1. Clear the DTCs.

      Click here


      1. Powertrain > Radar Cruise > Clear DTCs


    2. Make sure that the DTC detection conditions are met.

      Tip:

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

    3. Check for DTCs.

      Click here


      1. Powertrain > Radar Cruise > Trouble Codes


      Note:

      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.

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

    • A

      END (MILLIMETER WAVE RADAR SENSOR ASSEMBLY WAS DEFECTIVE)

    • B

      REPLACE DRIVING SUPPORT ECU ASSEMBLYClick here