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.

When the millimeter wave radar sensor assembly detects a malfunction in the skid control buzzer 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), 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.

  • Harness or connector

  • Skid control buzzer

  • Driving support ECU assembly

WIRING DIAGRAM

E342636E01

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. CHECK FOR DTC

    1. Clear the DTCs.

      Click here

      Body Electrical > Pre-Crash 2 > Clear DTCs

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

      Click here

      Tip:

      If the detection conditions are not met, the system cannot detect the malfunction.

      Body Electrical > Pre-Crash 2 > Active Test

      Tester Display

      Measurement Item

      Control Range

      Diagnostic Note

      PCS Crash Alarm Buzzer

      Skid control buzzer

      ON/OFF

      Test possible with power switch on (IG), vehicle stopped

      Body Electrical > Pre-Crash 2 > Active Test

      Tester Display

      PCS Crash Alarm Buzzer

    3. Check for DTCs.

      Click here

      Body Electrical > Pre-Crash 2 > Trouble Codes

      OK

      DTC C1A4A is not output.

    Result

    Proceed to

    OK

    NG
    OK

    USE SIMULATION METHOD TO CHECK

    Click hereClick hereClick here

    NG

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

    1. B338290C80

      *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

      Switch Condition

      Specified Condition

      G74-2 (IG1) - Body ground

      Power switch on (IG)

      11 to 14 V

      G74-2 (IG1) - Body ground

      Power switch off

      Below 1 V

    Result

    Proceed to

    OK

    NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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

    1. Disconnect the G74 skid control buzzer connector.

    2. Disconnect the G168 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

      G74-1 (BZ) - G168-3 (BZ)

      Always

      Below 1 Ω

      G74-1 (BZ) - Body ground

      Always

      10 kΩ or higher

    Result

    Proceed to

    OK

    NG
    OK

    INSPECT SKID CONTROL BUZZER (CONFIRM BUZZER OPERATION)Click here

    NG

  4. REPAIR OR REPLACE HARNESS OR CONNECTOR

    1. Repair or replace harness or connector.

    Result

    Proceed to

    NEXT
    NEXT

  5. CHECK FOR DTC

    1. Clear the DTCs.

      Click here

      Body Electrical > Pre-Crash 2 > Clear DTCs

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

      Click here

      Tip:

      If the detection conditions are not met, the system cannot detect the malfunction.

      Body Electrical > Pre-Crash 2 > Active Test

      Tester Display

      Measurement Item

      Control Range

      Diagnostic Note

      PCS Crash Alarm Buzzer

      Skid control buzzer

      ON/OFF

      Test possible with power switch on (IG), vehicle stopped

      Body Electrical > Pre-Crash 2 > Active Test

      Tester Display

      PCS Crash Alarm Buzzer

    3. Check for DTCs.

      Click here

      Body Electrical > Pre-Crash 2 > Trouble Codes

      OK

      DTC C1A4A is not output.

    Result

    Proceed to

    OK

    NG
    OK

    END (HARNESS OR CONNECTOR WAS DEFECTIVE)

    NG

  6. INSPECT SKID CONTROL BUZZER (CONFIRM BUZZER OPERATION)

    1. Turn the power switch on (IG).

    2. Check if the skid control buzzer assembly is sounding.

    Result

    Result

    Proceed to

    The skid control buzzer assembly does not sound when the power switch is on (IG)

    A

    The skid control buzzer assembly sounds continuously when the power switch is on (IG)

    B
    B

    REPLACE SKID CONTROL BUZZERClick here

    A

  7. INSPECT SKID CONTROL BUZZER (UNIT INSPECTION)

    1. Remove the skid control buzzer assembly.

      Click here

    2. Inspect the skid control buzzer assembly.

      Click here

    Result

    Result

    Proceed to

    Skid control buzzer assembly is abnormal

    A

    Skid control buzzer assembly is normal

    B
    B

    CHECK FOR DTCsClick here

    A

  8. REPLACE SKID CONTROL BUZZER

    1. Replace the skid control buzzer assembly.

      Click here

    Result

    Proceed to

    NEXT
    NEXT

  9. CHECK FOR DTCs

    1. Clear the DTCs.

      Click here

      Body Electrical > Pre-Crash 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.

      Tip:

      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-Crash 2 > Active Test

      Tester Display

      Measurement Item

      Control Range

      Diagnostic Note

      PCS Crash Alarm Buzzer

      Skid control buzzer assembly

      ON / OFF

      Test possible with power switch on (IG), vehicle stopped

    3. Check for DTCs.

      Click here

      Body Electrical > Pre-Crash 2 > Trouble Codes

    Result

    Result

    Proceed to

    DTC C1A4A is not output

    A

    DTC C1A4A is output

    B
    A

    END (SKID CONTROL BUZZER WAS DEFECTIVE)

    B

    REPLACE DRIVING SUPPORT ECU ASSEMBLY

    for LHD:Click here

    for RHD:Click here