AIR CONDITIONING SYSTEM(for Manual Air Conditioning System), Diagnostic DTC:B1497

DTC Code DTC Name
B1497 Communication Malfunction (Bus Ic)

DESCRIPTION

The air conditioning harness assembly connects the air conditioning amplifier assembly and the servo motors. The air conditioning amplifier assembly supplies power and sends operation instructions to each servo motor through the air conditioning harness assembly. Each servo motor sends damper position information to the air conditioning amplifier assembly.

DTC No. Detection Item DTC Detection Condition Trouble Area Memory
B1497 Communication Malfunction (Bus Ic) Error or open in communication line

  • Air conditioning harness assembly

  • No. 1 air conditioning radiator damper servo sub-assembly

  • No. 2 air conditioning radiator damper servo sub-assembly

  • Air conditioning amplifier assembly

Memorized

(10 sec. or more)*

WIRING DIAGRAM

B006WZYE01

PROCEDURE


  1. PERFORM ACTIVE TEST USING GTS


    1. Disconnect the No. 1 air conditioning radiator damper servo sub-assembly connector.

    2. Connect the GTS to the DLC3.

    3. Turn the ignition switch to ON.

    4. Turn the GTS on.

    5. Enter the following menus: Body Electrical / Air Conditioner / Active test.

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


      Body Electrical > Air Conditioner > Active Test
      Tester Display Measurement Item Control Range Diagnostic Note
      Air Mix Servo Targ Pulse(D) No. 1 air conditioning radiator damper servo sub-assembly (air mix) pulse

      Min.: 128

      Max.: 383

        for LHD:

      • Operates between 165 to 257 pulses


        for RHD:

      • Operates between 255 to 347 pulses
      A/O Servo Pulse(Rr D) No. 2 air conditioning radiator damper servo sub-assembly pulse

      Min.: 128

      Max.: 383

      		 Operates between 158 to 260 pulses

      Body Electrical > Air Conditioner > Active Test
      Tester Display
      Air Mix Servo Targ Pulse(D)

      Body Electrical > Air Conditioner > Active Test
      Tester Display
      A/O Servo Pulse(Rr D)
      Result
      Result Proceed to
      All of the damper servo motors are malfunctioning A
      One of the damper servo motors is malfunctioning B

    B

    PERFORM ACTIVE TEST USING GTS Click here

    A

  2. PERFORM ACTIVE TEST USING GTS


    1. Disconnect the No. 1 air conditioning radiator damper servo sub-assembly connector.

    2. Connect the GTS to the DLC3.

    3. Turn the ignition switch to ON.

    4. Turn the GTS on.

    5. Enter the following menus: Body Electrical / Air Conditioner / Active test.

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


      Body Electrical > Air Conditioner > Active Test
      Tester Display Measurement Item Control Range Diagnostic Note
      A/O Servo Pulse(Rr D) No. 2 air conditioning radiator damper servo sub-assembly pulse

      Min.: 128

      Max.: 383

      		 Operates between 158 to 260 pulses

      Body Electrical > Air Conditioner > Active Test
      Tester Display
      A/O Servo Pulse(Rr D)
      OK
      The damper servo motor operates smoothly.
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE NO. 1 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY Click here

    NG

  3. INSPECT AIR CONDITIONING AMPLIFIER ASSEMBLY

    B006YCZC13
    *a

    Component with harness connected

    (Air Conditioning Amplifier Assembly)

    Note

    When inspecting the air conditioning amplifier assembly, do not bring the tester probes too close to each other as a short circuit may occur.


    1. Disconnect the z8 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
      z8-2 (BUS G) - Body ground Always Below 1 Ω

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      z8-4 (B BUS) - Body ground Ignition switch ON 11 to 14 V

    4. Turn the ignition switch to ON.

    5. Using an oscilloscope, check the waveform.

      Item Content
      Terminal No. z8-3 (BUS) - z8-2 (BUS G)
      Tool Setting 2 V/DIV., 2 ms./DIV.
      Condition Ignition switch ON
      OK
      Waveform is similar to that shown in the illustration.

      Tech Tips

      The waveform varies with the blower speed.

      Result
      Proceed to
      OK
      NG

    OK

    REPLACE AIR CONDITIONING HARNESS ASSEMBLY Click here

    NG

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

  4. PERFORM ACTIVE TEST USING GTS


    1. Disconnect the No. 1 air conditioning radiator damper servo sub-assembly connector.

    2. Connect the GTS to the DLC3.

    3. Turn the ignition switch to ON.

    4. Turn the GTS on.

    5. Enter the following menus: Body Electrical / Air Conditioner / Active test.

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


      Body Electrical > Air Conditioner > Active Test
      Tester Display Measurement Item Control Range Diagnostic Note
      Air Mix Servo Targ Pulse(D) No. 1 air conditioning radiator damper servo sub-assembly (air mix) pulse

      Min.: 128

      Max.: 383

        for LHD:

      • Operates between 165 to 257 pulses


        for RHD:

      • Operates between 255 to 347 pulses
      A/O Servo Pulse(Rr D) No. 2 air conditioning radiator damper servo sub-assembly pulse

      Min.: 128

      Max.: 383

      		 Operates between 158 to 260 pulses

      Body Electrical > Air Conditioner > Active Test
      Tester Display
      Air Mix Servo Targ Pulse(D)

      Body Electrical > Air Conditioner > Active Test
      Tester Display
      A/O Servo Pulse(Rr D)
      Result
      Result Proceed to
      Only the No. 1 air conditioning radiator damper servo sub-assembly does not operate A
      Only the No. 2 air conditioning radiator damper servo sub-assembly does not operate B

    B

    REPLACE AIR CONDITIONING HARNESS ASSEMBLY Click here

    A

  5. INSPECT AIR CONDITIONING HARNESS ASSEMBLY (AIR CONDITIONING AMPLIFIER ASSEMBLY - NO. 1 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY)


    1. Disconnect the z8 air conditioning amplifier assembly connector.

    2. Disconnect the No. 1 air conditioning radiator damper servo sub-assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      z8-2 (BUS G) - A-3 (GND) Always Below 1 Ω
      z8-3 (BUS) - A-2 (LIN) Always Below 1 Ω
      z8-4 (B BUS) - A-1 (+B) Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE NO. 1 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY Click here

    NG

    REPLACE AIR CONDITIONING HARNESS ASSEMBLY Click here