PRE-COLLISION SYSTEM, Diagnostic DTC:C1A4A

DTC Code DTC Name
C1A4A Skid Control Buzzer Circuit

DESCRIPTION

The millimeter wave radar sensor assembly is connected to the forward recognition camera via CAN communication.

The millimeter wave radar sensor assembly operates the pre-collision alarm by sending a buzzer request signal to the pre-collision city buzzer.

If the millimeter wave radar sensor assembly detects a malfunction in the pre-collision city buzzer circuit, it stores DTC C1A4A.

DTC No. Detection Item DTC Detection Condition Trouble Area
C1A4A Skid Control Buzzer Circuit

When the ignition switch to ON and the pre-collision alarm is operating, either of the following conditions is met:


  • A buzzer request signal is sent to the pre-collision city buzzer but the buzzer does not sound for 0.3 seconds or more.

  • A buzzer request signal is not sent to the pre-collision city buzzer but the buzzer sounds for 0.3 seconds or more.

  • Pre-collision city buzzer

  • Forward recognition camera

  • Millimeter wave radar sensor assembly

  • Wire harness or connector
DTC Detection Conditions:
Vehicle Condition
Pattern 1 Pattern 2
Diagnosis Condition When the ignition switch to ON and the pre-collision alarm is operating. ○ ○
Malfunction Status A buzzer request signal is sent to the pre-collision city buzzer but the buzzer does not sound. ○ -
A buzzer request signal is not sent to the pre-collision city buzzer but the buzzer sound. - ○
Detection Time 0.3 seconds 0.3 seconds
Number of Trips 1 trip 1 trip

Tech Tips

DTC will be output when conditions for either of the patterns in the table above are met.

WIRING DIAGRAM

A001UYJE03

CAUTION / NOTICE / HINT

Note


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

  • When replacing the millimeter wave radar sensor assembly, always replace it with a new one.

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

    Click here

  • If the forward recognition camera has been replaced with a new one, be sure to perform Forward Recognition Axis Adjustment.

    Click here

  • When a malfunction occurs in the communication line to the forward recognition camera, U023A and/or U1002 is output. If a DTC related to the CAN communication line is output, first troubleshoot the CAN communication line.

    Click here

PROCEDURE


  1. CHECK FOR DTCs (PRE-COLLISION SYSTEM)


    1. Clear the DTCs.

      Click here


      Body Electrical > Pre-Collision 2 > Clear DTCs

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

      Click here

      Note

      Perform the Active Test for 1 second or more.

      Tech Tips

      Performing the Active Test for 1 second or more causes DTC C1A4A to be stored if the DTC detection conditions are met.


      Body Electrical > Pre-Collision 2 > Active Test
      Tester Display Measurement Item Control Range Diagnostic Note
      PCS Collision Alarm Buzzer Pre-collision city buzzer ON / OFF

      Test possible with ignition switch to ON

      Vehicle condition: Vehicle stopped

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

    3. Check for DTCs.

      Click here


      Body Electrical > Pre-Collision 2 > 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

  2. CHECK TERMINAL VOLTAGE


    1. A005PONC12
      *a

      Front view of wire harness connector

      (to Pre-collision City Buzzer)

      Disconnect the pre-collision city buzzer connector.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      F54-2 (IG1) - Body ground Ignition switch ON 11 to 14 V
      Ignition switch off Below 1 V

    3. Connect the F54 pre-collision city buzzer connector.

      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (PRE-COLLISION CITY BUZZER - BATTERY)

    OK

  3. CHECK HARNESS AND CONNECTOR (PRE-COLLISION CITY BUZZER - FORWARD RECOGNITION CAMERA)


    1. Disconnect the F54 pre-collision city buzzer connector.

    2. Disconnect the R5 forward recognition camera connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      F54-1 (BZ) - R5-8 (BZ) Always Below 1 Ω
      F54-1 (BZ) or R5-8 (BZ) - Body ground Always 10 kΩ or higher

    4. Connect the R5 forward recognition camera connector.

    5. Connect the F54 pre-collision city buzzer connector.

      Result
      Proceed to
      OK
      NG

    OK

    GO TO STEP 6 Click here

    NG

  4. REPAIR OR REPLACE HARNESS OR CONNECTOR (PRE-COLLISION CITY BUZZER - FORWARD RECOGNITION CAMERA)


    1. Repair or replace the harness or connector.

      Result
      Proceed to
      NEXT

    NEXT

  5. CHECK FOR DTCs (PRE-COLLISION SYSTEM)


    1. Clear the DTCs.

      Click here


      Body Electrical > Pre-Collision 2 > Clear DTCs

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

      Click here

      Note

      Perform the Active Test for 1 second or more.

      Tech Tips

      Performing the Active Test for 1 second or more causes DTC C1A4A to be stored if the DTC detection conditions are met.


      Body Electrical > Pre-Collision 2 > Active Test
      Tester Display Measurement Item Control Range Diagnostic Note
      PCS Collision Alarm Buzzer Pre-collision city buzzer ON / OFF

      Test possible with ignition switch to ON

      Vehicle condition: Vehicle stopped

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

    3. Check for DTCs.

      Click here


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

    A

    END

    B

  6. INSPECT PRE-COLLISION CITY BUZZER (CONFIRM BUZZER OPERATION)


    1. Turn the ignition switch to ON.

    2. Check if the pre-collision city buzzer is sounding.

      Result
      Result Proceed to
      The pre-collision city buzzer does not sound when the ignition switch to ON A
      The pre-collision city buzzer sounds continuously when the ignition switch to ON B

    B

    GO TO STEP 8 Click here

    A

  7. INSPECT PRE-COLLISION CITY BUZZER (UNIT INSPECTION)


    1. Remove the pre-collision city buzzer.

      for LHD: Click here

      for RHD: Click here

    2. Inspect the pre-collision city buzzer.

      for LHD: Click here

      for RHD: Click here

      Result
      Result Proceed to
      Pre-collision city buzzer is abnormal A
      Pre-collision city buzzer is normal B

    B

    GO TO STEP 9 Click here

    A

  8. REPLACE PRE-COLLISION CITY BUZZER


    1. Replace the pre-collision city buzzer.

      for LHD: Click here

      for RHD: Click here

      Result
      Proceed to
      NEXT

    NEXT

  9. CHECK FOR DTCs (PRE-COLLISION SYSTEM)


    1. Clear the DTCs.

      Click here


      Body Electrical > Pre-Collision 2 > Clear DTCs

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

      Click here

      Note

      Perform the Active Test for 1 second or more.

      Tech Tips

      Performing the Active Test for 1 second or more causes DTC C1A4A to be stored if the DTC detection conditions are met.


      Body Electrical > Pre-Collision 2 > Active Test
      Tester Display Measurement Item Control Range Diagnostic Note
      PCS Collision Alarm Buzzer Pre-collision city buzzer ON / OFF

      Test possible with ignition switch to ON

      Vehicle condition: Vehicle stopped

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

    3. Check for DTCs.

      Click here


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

    A

    END

    B

  10. REPLACE FORWARD RECOGNITION CAMERA


    1. Replace the forward recognition camera.

      Click here

    2. Perform Forward Recognition Axis Adjustment.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  11. CHECK FOR DTCs (PRE-COLLISION SYSTEM)


    1. Clear the DTCs.

      Click here


      Body Electrical > Pre-Collision 2 > Clear DTCs

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

      Click here

      Note

      Perform the Active Test for 1 second or more.

      Tech Tips

      Performing the Active Test for 1 second or more causes DTC C1A4A to be stored if the DTC detection conditions are met.


      Body Electrical > Pre-Collision 2 > Active Test
      Tester Display Measurement Item Control Range Diagnostic Note
      PCS Collision Alarm Buzzer Pre-collision city buzzer ON / OFF

      Test possible with ignition switch to ON

      Vehicle condition: Vehicle stopped

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

    3. Check for DTCs.

      Click here


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

    A

    END (FORWARD RECOGNITION CAMERA WAS DEFECTIVE)

    B

  12. REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY


    1. Replace the millimeter wave radar sensor assembly.

      Click here

    2. Adjust the millimeter wave radar sensor assembly.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  13. CLEAR DTC (PRE-COLLISION SYSTEM)


    1. Clear the DTCs.

      Click here


      Body Electrical > Pre-Collision 2 > Clear DTCs
      Result
      Proceed to
      NEXT

    NEXT

    END (MILLIMETER WAVE RADAR SENSOR ASSEMBLY WAS DEFECTIVE)