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. 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 assembly circuit for approximately 0.4 seconds or more.

  • Skid control buzzer assembly

  • Driving support ECU assembly

  • Harness or connector

WIRING DIAGRAM

B002EFDE45
*a from LH-IG1 RLY1 Relay
*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, make sure to replace it with a new one. If a device 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, and as a result, a DTC may be stored.

  • First check the CAN communication system by following How to Proceed with Troubleshooting. After checking that there are no malfunctions in the CAN communication system, proceed with troubleshooting.


PROCEDURE


  1. CHECK FOR DTCs (PRE-CRASH SAFETY SYSTEM)


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

      Click here


      Body Electrical > Pre-Crash 2 > Trouble Codes

      Tech Tips

      The dynamic radar cruise control system only stores DTC C1A4A when the vehicle speed reaches 36 km/h (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.

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

    B

    GO TO PRE-CRASH SAFETY SYSTEM Click here

    A

  2. 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.


      1. Turn the engine switch on (IG).

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

      3. Drive the vehicle at 36 km/h (22 mph) or more for 1 second or more.

    3. Check for DTCs.

      Click here


      Powertrain > Radar Cruise > Trouble Codes
      Result
      Result Proceed to
      DTC C1A4A is not output A
      DTC C1A4A is output B

    A

    USE SIMULATION METHOD TO CHECK Click here

    B

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


    1. Turn the engine switch on (IG).

    2. Check that the skid control buzzer assembly is sounds.

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

    B

    CHECK HARNESS AND CONNECTOR (SKID CONTROL BUZZER - DRIVING SUPPORT ECU ASSEMBLY) Click here

    A

  4. CHECK HARNESS AND CONNECTOR (SKID CONTROL BUZZER ASSEMBLY - BATTERY)


    1. B002CXCC89
      *a

      Front view of wire harness connector

      (to Skid Control Buzzer Assembly)

      Disconnect the skid control buzzer assembly connector.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      K1-2 (IG1) - Body ground Engine switch on (IG) 11 to 14 V
      K1-2 (IG1) - Body ground Engine switch off Below 1 V
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


    1. Disconnect the K1 skid control buzzer assembly connector.

    2. Disconnect the K4 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
      K1-1 (BZ) - K4-3 (BZ) Always Below 1 Ω
      K1-1 (BZ) or K4-3 (BZ) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. INSPECT SKID CONTROL BUZZER ASSEMBLY


    1. Remove the skid control buzzer.

      Click here

    2. Inspect the skid control buzzer.

      Click here

      Result
      Proceed to
      OK
      NG

    OK

    REPLACE DRIVING SUPPORT ECU ASSEMBLY Click here

    NG

    REPLACE SKID CONTROL BUZZER ASSEMBLY Click here

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


    1. Disconnect the K1 skid control buzzer connector.

    2. Disconnect the K4 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
      K1-1 (BZ) - K4-3 (BZ) Always Below 1 Ω
      K1-1 (BZ) or K4-3 (BZ) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE DRIVING SUPPORT ECU ASSEMBLY Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR