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 by sending a buzzer request signal to the skid control buzzer assembly.

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

DTC Code DTC Detection Condition Trouble Area
C1A4A

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


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

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

  • Skid control buzzer assembly

  • Driving support ECU assembly

  • Harness or connector

WIRING DIAGRAM

A000PY1E01
*a from LH-IG1 RLY1 Relay
*b Skid Control Buzzer Assembly
*c 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 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 DTCs (PRE-CRASH SAFETY SYSTEM)


    1. Clear the DTCs Click here.

    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.

      Pre-Crash 2
      Tester Display Test Part 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.

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

    A

    USE SIMULATION METHOD TO CHECK (SYMPTOM SIMULATION) Click here

    B

  2. CHECK TERMINAL VOLTAGE


    1. A000T1TE02
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Skid Control Buzzer Assembly)

      Disconnect the skid control buzzer assembly connector.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      N1-2 (IG1) - Body ground Power switch on (IG) 11 to 14 V
      Power switch off Below 1 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


    1. Disconnect the N1 skid control buzzer assembly connector.

    2. Disconnect the N173 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
      N1-1 (BZ) - N173-3 (BZ) Always Below 1 Ω
      N1-1 (BZ) or N173-3 (BZ) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (SKID CONTROL BUZZER ASSEMBLY - DRIVING SUPPORT ECU ASSEMBLY) Click here

    OK

  4. INSPECT SKID CONTROL BUZZER ASSEMBLY (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 BUZZER ASSEMBLY Click here

    A

  5. INSPECT SKID CONTROL BUZZER ASSEMBLY (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 is abnormal. A
      Skid control buzzer is normal. B

    B

    CHECK FOR DTCs (PRE-CRASH SAFETY SYSTEM) Click here

    A

  6. REPLACE SKID CONTROL BUZZER ASSEMBLY


    1. Replace the skid control buzzer assembly Click here.


    NEXT

  7. CHECK FOR DTCs (PRE-CRASH SAFETY SYSTEM)


    1. Clear the DTCs Click here.

    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.

      Pre-Crash 2
      Tester Display Test Part 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.

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

    A

    END

    B

    REPLACE DRIVING SUPPORT ECU ASSEMBLY Click here

  8. REPAIR OR REPLACE HARNESS OR CONNECTOR (SKID CONTROL BUZZER ASSEMBLY - DRIVING SUPPORT ECU ASSEMBLY)


    1. Repair or replace the harness or connector.


    NEXT

  9. CHECK FOR DTCs (PRE-CRASH SAFETY SYSTEM)


    1. Clear the DTCs Click here.

    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.

      Pre-Crash 2
      Tester Display Test Part 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.

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

    A

    END

    B

  10. INSPECT SKID CONTROL BUZZER ASSEMBLY (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 BUZZER ASSEMBLY Click here

    A

  11. INSPECT SKID CONTROL BUZZER ASSEMBLY (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 is abnormal. A
      Skid control buzzer is normal. B

    B

    CHECK FOR DTCs (PRE-CRASH SAFETY SYSTEM) Click here

    A

  12. REPLACE SKID CONTROL BUZZER ASSEMBLY


    1. Replace the skid control buzzer assembly Click here.


    NEXT

  13. CHECK FOR DTCs (PRE-CRASH SAFETY SYSTEM)


    1. Clear the DTCs Click here.

    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.

      Pre-Crash 2
      Tester Display Test Part 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.

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

    A

    END

    B

    REPLACE DRIVING SUPPORT ECU ASSEMBLY Click here