DYNAMIC RADAR CRUISE CONTROL SYSTEM(for 6AR-FSE), Diagnostic DTC:C1A4A

DTC Code DTC Name
C1A4A Skid Control Buzzer Circuit

DESCRIPTION

Based on dynamic radar cruise control system operation, the driving support ECU assembly provides warnings to the driver by sounding the skid control buzzer assembly.

DTC C1A4A is stored when a malfunction is detected in the skid control buzzer assembly circuit.

DTC No. DTC Detection Condition Trouble Area
C1A4A While the vehicle speed is 36 km/h (or 22 mph) or more and the dynamic radar cruise control system is operating (vehicle-to-vehicle distance control mode), the driving support ECU assembly detected a malfunction in the skid control buzzer assembly circuit for approximately 0.3 seconds or more.

  • Skid control buzzer assembly

  • Driving support ECU assembly

  • Wire harness or connector

WIRING DIAGRAM

B001O4HE78
*a from IG1 NO. 4 Relay
*b ECU-IG1 NO. 3
*c Skid Control Buzzer Assembly
*d Driving Support ECU Assembly

CAUTION / NOTICE / HINT

Note


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

  • 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. CHECK FOR DTCs (DTC C1A4A (PRE-CRASH SAFETY SYSTEM))


    1. Check for DTCs of the pre-crash safety system Click here.

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

      Tech Tips

      The dynamic radar cruise control system only stores DTC C1A4A when the vehicle speed reaches 36 km/h (or 22 mph), however the pre-crash safety system stores this DTC at any vehicle speed. If DTC C1A4A is stored by the pre-crash safety system, perform troubleshooting of the pre-crash safety system first.


    B

    GO TO PRE-CRASH SAFETY SYSTEM Click here

    A

  2. CHECK FOR DTCs (DTC C1A4A (DYNAMIC RADAR CRUISE CONTROL SYSTEM))


    1. Connect the GTS to the DLC3.

    2. Turn the engine switch on (IG).

    3. Clear the DTCs Click here.

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

      Tech Tips

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

    5. Enter the following menus: Powertrain / Radar Cruise2 / Trouble Codes.

    6. Check for DTCs.

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

    7. Turn the engine switch off.


    B

    USE SIMULATION METHOD TO CHECK Click here

    A

  3. CHECK TERMINAL VOLTAGE


    1. Disconnect the H65 skid control buzzer assembly connector.

    2. B001NOZE01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Skid Control Buzzer Assembly)

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      H65-2 (IG1) - Body ground Engine switch on (IG) 11 to 14 V
      H65-2 (IG1) - Body ground Engine switch off Below 1 V

    3. Reconnect the H65 skid control buzzer assembly connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK HARNESS AND CONNECTOR (SKID CONTROL BUZZER ASSEMBLY - DRIVING SUPPORT ECU ASSEMBLY)


    1. Disconnect the H65 skid control buzzer assembly connector.

    2. Disconnect the H194 driving support ECU assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      H65-1 (BZ) - H194-3 (BZ) Always Below 1 Ω
      H65-1 (BZ) or H194-3 (BZ) - Body ground Always 10 kΩ or higher
      Result
      Result Proceed to
      NG A
      OK B

    4. Reconnect the H194 driving support ECU assembly connector.

    5. Reconnect the H65 skid control buzzer assembly connector.


    B

    INSPECT SKID CONTROL BUZZER ASSEMBLY (CONFIRM BUZZER OPERATION) Click here

    A

  5. REPAIR OR REPLACE HARNESS OR CONNECTOR (SKID CONTROL BUZZER ASSEMBLY - DRIVING SUPPORT ECU ASSEMBLY)


    1. Repair or replace the harness or connector.


    NEXT

  6. CHECK FOR DTCs (DTC C1A4A (DYNAMIC RADAR CRUISE CONTROL SYSTEM))


    1. Connect the GTS to the DLC3.

    2. Turn the engine switch on (IG).

    3. Clear the DTCs Click here.

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

      Tech Tips

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

    5. Enter the following menus: Powertrain / Radar Cruise2 / Trouble Codes.

    6. Check for DTCs.

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

    7. Turn the engine switch off.


    B

    END

    A

  7. INSPECT SKID CONTROL BUZZER ASSEMBLY (CONFIRM BUZZER OPERATION)


    1. Turn the engine switch on (IG).

    2. Check if the skid control buzzer assembly is sounding.

      Result
      Result Proceed to
      The skid control buzzer assembly sounds continuously when the engine switch is on (IG). A
      The skid control buzzer assembly does not sound when the engine switch is on (IG). B

    B

    REPLACE SKID CONTROL BUZZER ASSEMBLY Click here

    A

  8. INSPECT SKID CONTROL BUZZER ASSEMBLY (UNIT INSPECTION)


    1. Remove the skid control buzzer assembly Click here.

    2. Inspect the skid control buzzer assembly Click here.

      Result
      Result Proceed to
      Skid control buzzer assembly is abnormal. A
      Skid control buzzer assembly is normal. B

    B

    CHECK FOR DTCs (DTC C1A4A (DYNAMIC RADAR CRUISE CONTROL SYSTEM)) Click here

    A

  9. REPLACE SKID CONTROL BUZZER ASSEMBLY


    1. Replace the skid control buzzer assembly Click here.


    NEXT

  10. CHECK FOR DTCs (DTC C1A4A (DYNAMIC RADAR CRUISE CONTROL SYSTEM))


    1. Connect the GTS to the DLC3.

    2. Turn the engine switch on (IG).

    3. Clear the DTCs Click here.

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

      Tech Tips

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

    5. Enter the following menus: Powertrain / Radar Cruise2 / Trouble Codes.

    6. Check for DTCs.

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

    7. Turn the engine switch off.


    A

    REPLACE DRIVING SUPPORT ECU ASSEMBLY Click here

    B

    END