CAN COMMUNICATION SYSTEM(for LHD without Central Gateway ECU) Air Conditioning Amplifier Communication Stop Mode

DESCRIPTION

Detection Item Symptom Trouble Area
Air Conditioning Amplifier Communication Stop Mode

Either Condition is met:


  • "Air Conditioning Amplifier" is not displayed on the "Bus Check" screen Click here.

  • Communication system DTCs (DTCs that start with U) that are output correspond to "Air Conditioning Amplifier Communication Stop Mode" in "DTC Combination Table" Click here.

  • Air conditioning amplifier assembly CAN branch wire or connector

  • Power source circuit of air conditioning amplifier assembly

  • Air conditioning amplifier assembly ground circuit

  • Air conditioning amplifier assembly

WIRING DIAGRAM

B001X4AE03
B001ZYNE03

CAUTION / NOTICE / HINT

Note


  • Before measuring the resistance of the CAN bus, turn the ignition switch off and leave the vehicle for 1 minute or more without operating the key, switches or opening or closing the doors. After that, disconnect the cable from the negative (-) battery terminal and leave the vehicle for 1 minute or more before measuring the resistance.

  • After turning the ignition switch off, waiting time may be required before disconnecting the cable from the battery terminal. Therefore, make sure to read the disconnecting the cable from the battery terminal notice before proceeding with work Click here.

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

Tech Tips


  • Operating the ignition switch, any switches or any doors triggers related ECU and sensor communication with the CAN, which causes resistance variation.

  • Even after DTCs are cleared, if a DTC is stored again after driving the vehicle for a while, the malfunction may be occurring due to vibration of the vehicle. In such a case, wiggling the ECUs or wire harness while performing the inspection below may help determine the cause of the malfunction.

PROCEDURE


  1. CHECK FOR OPEN IN CAN BUS WIRE (AIR CONDITIONING AMPLIFIER ASSEMBLY CAN BRANCH WIRE)


    1. Disconnect the cable from the negative (-) battery terminal.

    2. B001XPWE04
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to Air Conditioning Amplifier Assembly)

      for Automatic Air Conditioning System:


      1. Disconnect the air conditioning amplifier assembly connector.

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

        Standard Resistance
        Tester Connection Condition Specified Condition
        E35-3 (CANH) - E35-4 (CANL) Cable disconnected from negative (-) battery terminal 54 to 69 Ω
    3. B001VOLE01
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to Air Conditioning Amplifier Assembly)

      for Manual Air Conditioning System:


      1. Disconnect the air conditioning amplifier assembly connector.

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

        Standard Resistance
        Tester Connection Condition Specified Condition
        E81-11 (CANH) - E81-12 (CANL) Cable disconnected from negative (-) battery terminal 54 to 69 Ω

    NG

    REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO AIR CONDITIONING AMPLIFIER ASSEMBLY (CANH, CANL)

    OK

  2. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER ASSEMBLY - BATTERY AND BODY GROUND)


    1. Connect the cable to the negative (-) battery terminal.

      Note

      When connecting the cable, some systems need to be initialized after the cable is reconnected Click here.

    2. B001XH9E02
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to Air Conditioning Amplifier Assembly)

      for Automatic Air Conditioning System:


      1. Disconnect the air conditioning amplifier assembly connector.

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

        Standard Voltage
        Tester Connection Condition Specified Condition
        E36-6 (+B1) - Body ground Always 11 to 14 V
        E36-7 (+B2) - Body ground Always 11 to 14 V
        E36-5 (IG+) - Body ground Ignition switch ON 11 to 14 V

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

        Standard Resistance
        Tester Connection Condition Specified Condition
        E35-6 (E1) - Body ground Always Below 1 Ω
        E36-1 (GND) - Body ground Always Below 1 Ω
    3. B001ZV1E01
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to Air Conditioning Amplifier Assembly)

      for Manual Air Conditioning System:


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

        Standard Voltage
        Tester Connection Condition Specified Condition
        E81-21 (+B1) - Body ground Always 11 to 14 V
        E81-1 (IG+) - Body ground Ignition switch ON 11 to 14 V

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

        Standard Resistance
        Tester Connection Condition Specified Condition
        E81-14 (GND) - Body ground Always Below 1 Ω

    OK

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR