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 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

    w/o Full-speed range following function:

  • 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 assembly circuit for approximately 0.4 seconds or more.


    w/ Full-speed range following function:

  • While the vehicle speed is 5 km/h (3 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 assembly circuit for 0.4 seconds or more.

  • Skid control buzzer assembly

  • Driving support ECU assembly

  • Harness or connector

WIRING DIAGRAM

A000NMLE01
*a from IG Circuit
*b Skid Control Buzzer Assembly
*c 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. 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 Cruise / Active Test.

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

      Radar Cruise
      Tester Display Test Part Control Range Diagnostic Note
      Radar Cruise Approach Alarm Buzzer Skid control buzzer assembly ON or OFF Buzzer can be heard
      OK
      Skid control buzzer assembly sounds.

    NG

    CHECK TERMINAL VOLTAGE Click here

    OK

  2. CHECK FOR DTCs


    1. Clear the DTCs Click here.

    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.


      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. w/ Full-speed range following function: Drive the vehicle at 5 km/h (3 mph) or more for 0.4 seconds or more.

        w/o Full-speed range following function: Drive the vehicle at 36 km/h (22 mph) or more for 0.4 seconds or more.

    3. Check for DTCs Click here.

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

    A

    REPLACE DRIVING SUPPORT ECU ASSEMBLY Click here

    B

    USE SIMULATION METHOD TO CHECK Click here

  3. CHECK TERMINAL VOLTAGE


    1. Disconnect the E5 skid control buzzer assembly connector.

    2. A000SCFE01
      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
      N1-2 (IG1) - Body ground Power switch on (IG) 11 to 14 V
      N1-2 (IG1) - Body ground Power switch off Below 1 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. 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 normal. A
      Skid control buzzer assembly is abnormal. B

    B

    REPLACE SKID CONTROL BUZZER ASSEMBLY Click here

    A

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


    1. Disconnect the N1 skid control buzzer assembly connector.

    2. Disconnect the N173 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
      N1-1 (BZ) - N173-3 (BZ) Always Below 1 Ω
      N1-1 (BZ) or N173-3 (BZ) - Body ground Always 10 kΩ or higher

    OK

    REPLACE DRIVING SUPPORT ECU ASSEMBLY Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR