DYNAMIC RADAR CRUISE CONTROL SYSTEM, 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.

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

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

C1A4A

Skid Control Buzzer Circuit

While the vehicle speed is 36 km/h (22 mph) or more and the dynamic radar cruise control system is operating, the driving support ECU assembly detects a malfunction in the skid control buzzer circuit for approximately 0.3 seconds or more.

  • Skid control buzzer

  • Driving support ECU assembly

  • Harness or connector

WIRING DIAGRAM

B403796E53

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. 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: Powertrain / Radar Cruise2 / Active Test.

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

      Powertrain > Radar Cruise2 > Active Test

      Skid control buzzer (approach sound)

      Tester Display

      Measurement Item

      Control Range

      Diagnostic Note

      Radar Cruise Approach Alarm Buzzer

      Skid control buzzer assembly (approach sound)

      ON or OFF

      Buzzer can be heard

      Powertrain > Radar Cruise2 > Active Test

      Tester Display

      Radar Cruise Approach Alarm Buzzer

      OK

      Skid control buzzer sounds.

    Result

    Proceed to

    OK

    NG
    NG

    CHECK TERMINAL VOLTAGEClick here

    OK

  2. CHECK FOR DTCs

    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Clear the DTCs.

      Click here

      Powertrain > Radar Cruise2 > Clear DTCs

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

      Tip:

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

      1. Turn the power switch on (IG).

      2. Turn the dynamic radar cruise control system on using the cruise control main switch (ON/OFF).

      3. Drive the vehicle at 36 km/h (22 mph) or more for 0.3 seconds or more.

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

    6. Check for DTCs.

      Click here

      Powertrain > Radar Cruise2 > Trouble Codes

      Result

      Result

      Proceed to

      DTC C1A4A is output

      A

      DTC C1A4A is not output

      B
    A

    REPLACE DRIVING SUPPORT ECU ASSEMBLY

    B

    USE SIMULATION METHOD TO CHECK

    Click hereClick hereClick here

  3. CHECK TERMINAL VOLTAGE

    1. B338290C77

      *a

      Front view of wire harness connector

      (to Skid Control Buzzer)

      Disconnect the skid control buzzer connector.

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

      Standard Voltage

      Tester Connection

      Switch Condition

      Specified Condition

      G74-2 (IG1) - Body ground

      Power switch on (IG)

      11 to 14 V

      G74-2 (IG1) - Body ground

      Power switch off

      Below 1 V

    Result

    Proceed to

    OK

    NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. INSPECT SKID CONTROL BUZZER

    1. Remove the skid control buzzer.

      Click here

    2. Inspect the skid control buzzer.

      Click here

    Result

    Result

    Proceed to

    Skid control buzzer is abnormal.

    A

    Skid control buzzer is normal.

    B
    B

    REPLACE SKID CONTROL BUZZER

    Click here

    A

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

    1. Disconnect the G74 skid control buzzer connector.

    2. Disconnect the G168 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

      G74-1 (BZ) - G168-3 (BZ)

      Always

      Below 1 Ω

      G74-1 (BZ) or G168-3 (BZ) - Body ground

      Always

      10 kΩ or higher

    Result

    Proceed to

    OK

    NG
    OK

    REPLACE DRIVING SUPPORT ECU ASSEMBLY

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR