PRE-CRASH SAFETY SYSTEM, Diagnostic DTC:C1A4A

DTC Code DTC Name
C1A4A Skid Control Buzzer Circuit

DESCRIPTION

The driving support ECU assembly operates the pre-crash alarm control by sending a buzzer request signal to the skid control buzzer.

If the driving support ECU assembly detects a malfunction in the skid control buzzer circuit, it stores DTC C1A4A.

DTC No. DTC Detection Condition Trouble Area
C1A4A

When the engine switch is on (IG) and the pre-crash alarm control is operating, either of the following conditions is met:


  • A buzzer request signal is sent to the skid control buzzer but the buzzer does not sound for 1 second or more.

  • A buzzer request signal is not sent to the skid control buzzer but the buzzer sounds for 1 second or more.

  • Skid control buzzer

  • Driving support ECU assembly

  • Harness or connector

WIRING DIAGRAM

B0018BLE83
*a from IG NO.4 Relay
*b ECU-IG NO. 6
*c Skid Control Buzzer
*d 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 it will not match the information from the vehicle and a DTC may be stored.

PROCEDURE


  1. CHECK DTC OUTPUT (PRE-CRASH SAFETY SYSTEM)


    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 / Trouble Codes.

    5. Clear the DTCs Click here.

    6. Enter the following menus: Body Electrical / Pre-Crash 2 / Active Test.

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

      Note

      Perform the Active Test for 1 second or more.

      Tech Tips

      This DTC can be stored by performing the Active Test.

      Pre-Crash 2
      Tester Display Test Part Control Range Diagnostic Note
      PCS Crash Alarm Buzzer Skid control buzzer ON/OFF Test possible with engine switch on (IG), vehicle stopped

    8. Check for DTCs Click here.

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

    B

    USE SIMULATION METHOD TO CHECK (SYMPTOM SIMULATION) Click here

    A

  2. CHECK TERMINAL VOLTAGE


    1. B001AKOE01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Skid Control Buzzer)

      Disconnect the skid control buzzer connector.

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

      Standard Voltage :
      Tester Connection Condition Specified Condition
      E5-2 (IG1) - Body ground Engine switch on (IG) 11 to 14 V
      E5-2 (IG1) - Body ground Engine switch off Below 1 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


    1. Disconnect the skid control buzzer connector.

    2. Disconnect the 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
      E5-1 (BZ) - E138-3 (BZ) Always Below 1 Ω
      E5-1 (BZ) orE138-3 (BZ) - Body ground Always 10 kΩ or higher
      Result
      Result Proceed to
      NG A
      OK B

    B

    INSPECT SKID CONTROL BUZZER (CONFIRM BUZZER OPERATION) Click here

    A

  4. REPAIR OR REPLACE HARNESS OR CONNECTOR


    1. Repair or replace the harness or connector.


    NEXT

  5. CHECK DTC OUTPUT (PRE-CRASH SAFETY SYSTEM)


    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 / Trouble Codes.

    5. Clear the DTCs Click here.

    6. Enter the following menus: Body Electrical / Pre-Crash 2 / Active Test.

    7. Perform "Active Test" according to the display on the GTS.

      Note

      Perform the Active Test for 1 second or more.

      Tech Tips

      This DTC can be stored by performing the Active Test.

      Pre-Crash 2
      Tester Display Test Part Control Range Diagnostic Note
      PCS Crash Alarm Buzzer Skid control buzzer ON/OFF Test possible with engine switch on (IG), vehicle stopped

    8. Check for DTCs Click here.

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

    B

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    A

  6. INSPECT SKID CONTROL BUZZER (CONFIRM BUZZER OPERATION)


    1. Turn the engine switch on (IG).

    2. Check if the skid control buzzer is sounding.

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

    B

    REPLACE SKID CONTROL BUZZER Click here

    A

  7. INSPECT SKID CONTROL BUZZER (UNIT INSPECTION)


    1. Remove the skid control buzzer Click here.

    2. Inspect the skid control buzzer Click here.

      Result
      Result Proceed to
      Skid control buzzer is abnormal. A
      Skid control buzzer is normal. B

    B

    CHECK DTC OUTPUT (PRE-CRASH SAFETY SYSTEM) Click here

    A

  8. REPLACE SKID CONTROL BUZZER


    1. Replace the skid control buzzer Click here.


    NEXT

  9. CHECK DTC OUTPUT (PRE-CRASH SAFETY SYSTEM)


    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 / Trouble Codes.

    5. Clear the DTCs Click here.

    6. Enter the following menus: Body Electrical / Pre-Crash 2 / Active Test.

    7. Perform "Active Test" according to the display on the GTS.

      Note

      Perform the Active Test for 1 second or more.

      Tech Tips

      This DTC can be stored by performing the Active Test.

      Pre-Crash 2
      Tester Display Test Part Control Range Diagnostic Note
      PCS Crash Alarm Buzzer Skid control buzzer ON/OFF Test possible with engine switch on (IG), vehicle stopped

    8. 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

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  10. CHECK DTC OUTPUT (PRE-CRASH SAFETY SYSTEM)


    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 / Trouble Codes.

    5. Clear the DTCs Click here.

    6. Enter the following menus: Body Electrical / Pre-Crash 2 / Active Test.

    7. Perform "Active Test" according to the display on the GTS.

      Note

      Perform the Active Test for 1 second or more.

      Tech Tips

      This DTC can be stored by performing the Active Test.

      Pre-Crash 2
      Tester Display Test Part Control Range Diagnostic Note
      PCS Crash Alarm Buzzer Skid Control Buzzer ON/OFF Test possible with engine switch on (IG), vehicle stopped

    8. 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