PRE-CRASH SAFETY SYSTEM, Diagnostic DTC:C1A4A

DTC Code DTC Name
C1A4A Skid Control Buzzer Circuit

DESCRIPTION

Based on pre-crash 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 power 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

  • Wire harness or connector

  • Millimeter wave radar sensor assembly

  • Driving support ECU assembly

WIRING DIAGRAM

A005EV5E13

CAUTION / NOTICE / HINT

Note


  • When the millimeter wave radar sensor is replaced with a new one, adjustment of the radar sensor beam axis must be performed Click here.

  • Before performing the inspection, check that DTC U0235, U1002 or U1104 is not output.

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

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 power 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 the GTS.

      Pre-Crash 2
      Tester Display Test Part 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
      Result
      Result Proceed to
      Skid control buzzer assembly does not sound A
      Skid control buzzer assembly sounds B

    B

    REPLACE DRIVING SUPPORT ECU ASSEMBLY Click here

    A

  2. INSPECT SKID CONTROL BUZZER ASSEMBLY


    1. Remove the skid control buzzer assembly Click here.

    2. Inspect the skid control buzzer assembly Click here.


    NG

    REPLACE SKID CONTROL BUZZER ASSEMBLY Click here

    OK

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


    1. A005DGHE02
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Skid Control Buzzer Assembly)

      Disconnect the L46 control buzzer assembly connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      L46-2 (IG1) - Body ground Power switch on (IG) 11 to 14 V
      L46-2 (IG1) - Body ground Power switch off Below 1 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


    1. Disconnect the L46 control buzzer assembly connector.

    2. Disconnect the A76 ter wave radar sensor assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      L46-1 (BZ) - A76-10 (BZ) Always Below 1 Ω
      L46-1 (BZ) or A76-10 (BZ) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY


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


    NEXT

  6. ADJUST MILLIMETER WAVE RADAR SENSOR ASSEMBLY


    1. Perform millimeter wave radar sensor assembly adjustment Click here.


    NEXT

  7. CHECK DTC OUTPUT (PRE-CRASH SYSTEM)


    1. Using the GTS, enter the following menus: Body Electrical / Pre-Crash 2 / Trouble Codes.

    2. Clear the DTCs Click here.

    3. Recheck for DTCs.

      OK
      DTC C1A4A is not output.

    OK

    END (MILLIMETER WAVE RADAR SENSOR ASSEMBLY WAS DEFECTIVE)

    NG

    REPLACE DRIVING SUPPORT ECU ASSEMBLY Click here