LANE-KEEPING ASSIST SYSTEM, Diagnostic DTC:C1A6A

DTC Code DTC Name
C1A6A Infrared Signal Circuit

DESCRIPTION

In order to increase the ability to detect obstacles at night, the object recognition ECU receives information about the headlight assembly illumination, exterior vehicle brightness and vehicle speed from the driving support ECU to automatically control the near infrared ray illumination.

If a headlight assembly illumination malfunction or automatic light sensor signal malfunction is detected, low beam or near infrared light signal input from the headlight assembly indicate an open circuit, a signal is sent to the driving support ECU and DTC C1A6A is output.

DTC Code DTC Detection Condition Trouble Area
C1A6A

When one of the following conditions is met while the power switch is on (IG):


  • An automatic light control sensor signal malfunction continues for 3 seconds or more.

  • An automatic light control sensor communication stop malfunction occurs.

  • A headlight assembly combination signal malfunction continues for 10 seconds or more.

  • A headlight assembly malfunction signal continues for 4 seconds or more.

  • A communication malfunction with the headlight swivel ECU assembly continues for 2.1 seconds or more.

  • An headlight swivel ECU assembly communication stop malfunction occurs.

  • Near infrared light open circuit.

  • A light failure indicator sensor open circuit between body ground continues for 30 seconds or more.

  • The wire harness between the object recognition ECU and headlight assembly has an open or short circuit for 30 seconds or more.

  • The type of infrared ray light that is learned is incorrect.

  • Lighting system

  • CAN communication system

  • Harness or connector

  • Headlight unit

  • Object recognition ECU

  • Multiplex network front light ECU

Note

After replacing the object recognition ECU, if the headlight assembly is not connected when the power switch is turned on (IG), the ECU records the wrong headlight type and outputs DTC C1A6A.

WIRING DIAGRAM

A01GX3HE02

INSPECTION PROCEDURE

Note

Inspect the fuses and bulbs for circuits related to this system before performing the following inspection procedure.

PROCEDURE


  1. CHECK LIGHTING SYSTEM


    1. Check if the lighting system is malfunctioning Click here.

      OK
      No malfunctions are present in the lighting system.

    NG

    GO TO LIGHTING SYSTEM Click here

    OK

  2. CHECK CAN COMMUNICATION SYSTEM


    1. Use the intelligent tester to check if the CAN communication system is functioning normally.


      Result
      Result Proceed to
      CAN communication DTCs are not output. A
      CAN communication DTCs are output. (for LHD) B
      CAN communication DTCs are output. (for RHD) C

    B

    GO TO CAN COMMUNICATION SYSTEM Click here

    C

    GO TO CAN COMMUNICATION SYSTEM Click here

    A

  3. PERFORM ACTIVE TEST USING INTELLIGENT TESTER


    1. Select the Active Test, use the intelligent tester to generate a control command, and then check that the near infrared ray emitter operates Click here.

      Pre-Crash 2
      Tester Display Test Part Control Range Diagnostic Note
      Infrared Signal Status Near infrared ray emitter operates ON/OFF -
      OK
      A blurred light is emitted.

    NG

    CHECK HARNESS AND CONNECTOR (HEADLIGHT ASSEMBLY - MULTIPLEX NETWORK FRONT LIGHT ECU AND BODY GROUND) Click here

    OK

  4. CHECK OBJECT RECOGNITION ECU


    1. A01H0D5E28

      Using the intelligent tester, enter the following menus: Body Electrical / Pre-Crash 2 / Active Test. Click here

    2. Select "Infrared Signal Status", and perform the Active Test.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      p1-11 (IRFP) - Body ground

      • Power switch on (IG)

      • Active Test is performed

      		 Auxiliary battery voltage x 0.3 to Auxiliary battery x 0.6 V

    NG

    CHECK HARNESS AND CONNECTOR (HEADLIGHT ASSEMBLY - AUXILIARY BATTERY AND BODY GROUND) Click here

    OK

  5. CHECK OBJECT RECOGNITION ECU


    1. A01H0D5E31

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

      Standard Voltage
      for LH
      Tester Connection Switch Condition Specified Condition
      p1-7 (IRL) - Body ground Power switch on (IG) 11 to 14 V
      for RH
      Tester Connection Switch Condition Specified Condition
      p1-3 (IRR) - Body ground Power switch on (IG) 11 to 14 V

    NG

    CHECK HARNESS AND CONNECTOR (HEADLIGHT ASSEMBLY - OBJECT RECOGNITION ECU AND AUXILIARY BATTERY) Click here

    OK

    REPLACE OBJECT RECOGNITION ECU Click here

  6. CHECK HARNESS AND CONNECTOR (HEADLIGHT ASSEMBLY - OBJECT RECOGNITION ECU AND AUXILIARY BATTERY)


    1. A01GXKLE05

      Disconnect the B1*1 and/or B11*2 headlight connector.


      • *1: for LH

      • *2: for RH

    2. Disconnect the p1 object recognition ECU connector.

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

      Standard Voltage
      for LH
      Tester Connection Switch Condition Specified Condition
      B1-4 (SOL) - Body ground Power switch on (IG) 11 to 14 V
      for RH
      Tester Connection Switch Condition Specified Condition
      B11-4 (SOL) - Body ground Power switch on (IG) 11 to 14 V

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

      Standard Resistance
      for LH
      Tester Connection Condition Specified Condition
      B1-6 (IRFL) - p1-7 (IRL) Always Below 1 Ω
      B1-6 (IRFL) or p1-7 (IRL) - Body ground Always 10 kΩ or higher
      for RH
      Tester Connection Condition Specified Condition
      B11-6 (IRFR) - p1-3 (IRR) Always Below 1 Ω
      B11-6 (IRFR) or p1-3 (IRR) - Body ground Always 10 kΩ or higher
      Result
      Result Proceed to
      OK (for LH) A
      OK (for RH) B
      NG C

    B

    REPLACE HEADLIGHT UNIT RH Click here

    C

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    A

    REPLACE HEADLIGHT UNIT LH Click here

  7. CHECK HARNESS AND CONNECTOR (HEADLIGHT ASSEMBLY - AUXILIARY BATTERY AND BODY GROUND)


    1. A01GXR4E38

      Disconnect the B1*1 and/or B11*2 headlight connector.


      • *1: for LH

      • *2: for RH

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

      Standard Voltage
      for LH
      Tester Connection Switch Condition Specified Condition
      B1-15 (IGED) - Body ground Power switch on (IG) 11 to 14 V
      for RH
      Tester Connection Switch Condition Specified Condition
      B11-15 (IGED) - Body ground Power switch on (IG) 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  8. CHECK HARNESS AND CONNECTOR (HEADLIGHT ASSEMBLY - OBJECT RECOGNITION ECU)


    1. A01GXKLE06

      Disconnect the B1*1 and/or B11*2 headlight connector.


      • *1: for LH

      • *2: for RH

    2. Disconnect the p1 object recognition ECU connector.

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

      Standard Resistance
      for LH
      Tester Connection Condition Specified Condition
      B1-19 (IRL) - p1-11 (IRFP) Always Below 1 Ω
      B1-19 (IRL) or p1-11 (IRFP) - Body ground Always 10 kΩ or higher
      for RH
      Tester Connection Condition Specified Condition
      B11-19 (IRR) - p1-11 (IRFP) Always Below 1 Ω
      B11-19 (IRR) or p1-11 (IRFP) - Body ground Always 10 kΩ or higher
      Result
      Result Proceed to
      OK (for LH) A
      OK (for RH) B
      NG C

    B

    REPLACE HEADLIGHT UNIT RH Click here

    C

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    A

    REPLACE HEADLIGHT UNIT LH Click here

  9. CHECK HARNESS AND CONNECTOR (HEADLIGHT ASSEMBLY - MULTIPLEX NETWORK FRONT LIGHT ECU AND BODY GROUND)


    1. A01GZYYE07

      Disconnect the B1*1 and/or B11*2 headlight connector.


      • *1: for LH

      • *2: for RH

    2. Disconnect the B14 multiplex network front light ECU connector.

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

      Standard Resistance
      for LH
      Tester Connection Condition Specified Condition
      B1-2 (HI) - B14-6 (HLHL) Always Below 1 Ω
      B1-1 (E) - Body ground Always Below 1 Ω
      B1-2 (HI) or B14-6 (HLHL) - Body ground Always 10 kΩ or higher
      for RH
      Tester Connection Condition Specified Condition
      B11-2 (HI) - B14-5 (HLHR) Always Below 1 Ω
      B11-1 (E) - Body ground Always Below 1 Ω
      B11-2 (HI) or B14-5 (HLHR) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  10. CHECK MULTIPLEX NETWORK FRONT LIGHT ECU


    1. Temporarily replace the multiplex network front light ECU with a new or normally functioning one.

    2. Clear the DTCs Click here.

    3. Recheck for DTC Click here.

      Result
      Result Proceed to
      DTC C1A6A is not output A
      DTC C1A6A is output (for LH) B
      DTC C1A6A is output (for RH) C

    B

    REPLACE HEADLIGHT UNIT LH Click here

    C

    REPLACE HEADLIGHT UNIT RH Click here

    A

    END (MULTIPLEX NETWORK FRONT LIGHT ECU IS DEFECTIVE)