AIR CONDITIONING SYSTEM(for Automatic Air Conditioning System with Side-mounted Air Conditioner Pressure Sensor), 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)

Any of the following conditions is met:


  • Error in communication line

  • Open in communication line

  • Air conditioning harness assembly

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

  • Air conditioning amplifier assembly

Memorized

(10 seconds or more)*

DTC Detection Conditions
Vehicle Condition
Pattern 1 Pattern 2
Diagnosis Condition Ignition switch ON ○ ○
Malfunction Status Error in communication line ○ -
Open in communication line - ○
Detection Time 10 seconds or more 10 seconds or more
Number of Trips 1 trip 1 trip

Tech Tips

DTC will be output when conditions for either of the patterns in the table above are met.

WIRING DIAGRAM

A002YICE07

PROCEDURE


  1. PERFORM ACTIVE TEST USING GTS


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch ON.

    3. Turn the GTS on.

    4. Enter the following menus: Body Electrical / Air Conditioner / Active Test.

    5. 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 (driver side air mix) pulse

      Min.: 128

      Max.: 383

        for LHD:

      • Operates between 165 to 257 pulses


        for RHD:

      • Operates between 255 to 347 pulses

      Body Electrical > Air Conditioner > Active Test
      Tester Display
      Air Mix Servo Targ Pulse(D)
      OK
      No. 1 air conditioning radiator damper servo motor operates smoothly.
      Result
      Result Proceed to
      No. 1 air conditioning radiator damper servo motors are malfunctioning A
      No. 1 air conditioning radiator damper servo motors is normal B

    B

    CHECK FOR DTC* Click here

    A

  2. INSPECT AIR CONDITIONING HARNESS ASSEMBLY (AIR CONDITIONING AMPLIFIER ASSEMBLY - NO. 1 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-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 m1 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
      m1-2 (BUS G) - Body ground Always Below 1 Ω
      m1-3 (BUS) - 2 (LIN) Always Below 1 Ω
      m1-4 (BUSB) - 1 (+B) Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE AIR CONDITIONING HARNESS ASSEMBLY Click here

    OK

  3. INSPECT 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. Turn the ignition switch ON.

    2. A002YWOC07
      *a

      Component with harness connected

      (Air Conditioning Amplifier Assembly)

      Connect an oscilloscope to terminals m1-2 (BUS G) and m1-3 (BUS) of the air conditioning amplifier assembly and check the waveform.

      OK
      Waveform is similar to that shown in the illustration.

      Tech Tips

      The waveform varies with the blower speed.

      Item Content
      Tool Setting 2 V/DIV., 2 ms./DIV.
      Vehicle Condition Ignition switch ON.
      Result
      Proceed to
      OK
      NG

    OK

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

    NG

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

  4. CHECK FOR DTC*


    1. Clear the DTCs.

      Click here


      Body Electrical > Air Conditioner > Clear DTCs

    2. Check for DTCs.

      Click here


      Body Electrical > Air Conditioner > Trouble Codes
      Result
      Result Proceed to
      DTCs are not output A
      DTCs are output B

    A

    USE SIMULATION METHOD TO CHECK Click here

    B

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here