DYNAMIC RADAR CRUISE CONTROL SYSTEM, Diagnostic DTC:C1A4A

DTC Code DTC Name
C1A4A Skid Control Buzzer Circuit

DESCRIPTION

Based on pre-crash safety control, the driving support ECU assembly provides warnings to the driver. The driving support ECU assembly does this 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 While 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

WIRING DIAGRAM

B004F22E22

CAUTION / NOTICE / HINT

Note


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

  • 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

PROCEDURE


  1. CHECK FOR DTCs (RADAR CRUISE)


    1. Clear the DTCs.

      Click here


      Powertrain > Radar Cruise > Clear DTCs

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

      Tech Tips

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

    3. Check for DTCs.

      Click here


      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

    A

    USE SIMULATION METHOD TO CHECK Click here

    C

    GO TO DTC U0235 Click here

    D

    GO TO DTC U1104 Click here

    B

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


    1. Connect the GTS to the DLC3.

    2. Turn the power 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 GTS.


      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

      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

    OK

    REPLACE DRIVING SUPPORT ECU ASSEMBLY Click here

    NG

  3. INSPECT SKID CONTROL BUZZER ASSEMBLY


    1. Remove the skid control buzzer assembly.

      Click here

    2. Inspect the skid control buzzer assembly.

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE SKID CONTROL BUZZER ASSEMBLY Click here

    OK

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


    1. B004FTKC87
      *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 Power switch on (IG) 11 to 14 V
      O40-2 (IG1) - Body ground Power switch off Below 1 V
      Result
      Proceed to
      OK
      NG

    NG

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

    OK

  5. 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

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. 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.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  7. CHECK FOR DTCs (RADAR CRUISE)


    1. Clear the DTCs.

      Click here


      Powertrain > Radar Cruise > Clear DTCs

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

      Tech Tips

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

    3. Check for DTCs.

      Click here


      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 ASSEMBLY Click here