PRE-CRASH SAFETY 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 engine switch is on (IG), a skid control buzzer assembly circuit malfunction signal is received from the millimeter wave radar sensor assembly for 3 seconds or more.

  • Skid control buzzer assembly

  • Skid control buzzer circuit

  • Millimeter wave radar sensor assembly

  • Driving support ECU assembly

WIRING DIAGRAM

A018ME2E03

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 (PCS CRASH ALARM BUZZER, PCS APPROACH ALARM BUZZER)


    1. Connect the GTS to the DLC3.

    2. Turn the engine 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
      PCS Crash Alarm Buzzer Skid control buzzer assembly ON or OFF Buzzer can be heard
      PCS Approach Alarm Buzzer Skid control buzzer assembly ON or OFF Buzzer can be heard

      Body Electrical > Pre-Crash 2 > Active Test
      Tester Display
      PCS Crash Alarm Buzzer

      Body Electrical > Pre-Crash 2 > Active Test
      Tester Display
      PCS Approach Alarm Buzzer
      OK
      Skid control buzzer assembly sounds.
      Result
      Proceed to
      OK
      NG

    6. Turn the engine switch off.


    OK

    GO TO STEP 5 Click here

    NG

  2. 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

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


    1. A018I8KC09
      *a

      Front view of wire harness connector

      (to Skid Control Buzzer Assembly)

      Disconnect the A59 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
      A59-2 (IG1) - Body ground Engine switch on (IG) 11 to 14 V
      A59-2 (IG1) - Body ground Engine switch off Below 1 V

    3. Reconnect the A59 skid control buzzer assembly connector.

      Result
      Proceed to
      OK
      NG

    NG

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

    OK

  4. CHECK HARNESS AND CONNECTOR (SKID CONTROL BUZZER ASSEMBLY - MILLIMETER WAVE RADAR SENSOR ASSEMBLY)


    1. Disconnect the A59 skid control buzzer assembly connector.

    2. Disconnect the A3 millimeter wave radar sensor assembly connector.

    3. Disconnect the S4 lane departure warning camera connector (w/ Lane Departure Alert System).

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A59-1 (BZ) - A3-10 (BZ) Always Below 1 Ω
      A59-1 (BZ) or A3-10 (BZ) - Body ground Always 10 kΩ or higher

    5. Reconnect the S4 lane departure warning camera connector (w/ Lane Departure Alert System).

    6. Reconnect the A3 millimeter wave radar sensor assembly connector.

    7. Reconnect the A59 skid control buzzer assembly connector.

      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (SKID CONTROL BUZZER ASSEMBLY - MILLIMETER WAVE RADAR SENSOR ASSEMBLY)

    OK

  5. REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY


    1. Replace the millimeter wave radar sensor assembly with a new one.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  6. ADJUST MILLIMETER WAVE RADAR SENSOR ASSEMBLY


    1. Perform millimeter wave radar sensor assembly adjustment.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  7. CHECK FOR DTC (PRE-CRASH 2)


    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: Body Electrical / Pre-Crash 2 / Trouble Codes.

    6. Check for DTCs.


      Body Electrical > Pre-Crash 2 > Trouble Codes
      Result
      Result Proceed to
      DTC C1A4A is not output A
      DTC C1A4A is output B

    7. Turn the engine switch off.


    A

    END (MILLIMETER WAVE RADAR SENSOR ASSEMBLY WAS DEFECTIVE)

    B

    REPLACE DRIVING SUPPORT ECU ASSEMBLY Click here