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Home >> Lexus >> 2020 >> UX 200 Luxury >> Repair and Diagnosis >> External Pages >> Different car >> Section 60 (Air Conditioning System - Diagnostic Codes (1 Of 2) (Hybrid)) >> AIR CONDITIONING SYSTEM (for HV Model) >> DTC B1497: Communication Malfunction (Bus Ic) [10/2020 - ] >> Procedure

DTC B1497: Communication Malfunction (Bus Ic) [10/2020 - ]: Procedure

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  1. PERFORM ACTIVE TEST USING TECHSTREAM 
    1. Perform the Active Test according to the display on the Techstream.

      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      		 Operates between 165 and 257 pulses
      A/O Servo Pulse(Rr D) No. 2 air conditioning radiator damper servo sub-assembly pulse Min.: 128
      Max.: 383      		 Operates between 158 and 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

    Result: 

    B 

    See step  4

    Result: 

    A 

    See step  2

  2. PERFORM ACTIVE TEST USING TECHSTREAM 
    1. Disconnect the No. 1 air conditioning radiator damper servo sub-assembly connector.
    2. Perform the Active Test according to the display on the Techstream.

      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 and 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

    Result: 

    OK 

    REPLACE NO. 1 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY. Refer to  DISASSEMBLY [10/2020 - ] 

    Result: 

    NG 

    See step  3

  3. INSPECT AIR CONDITIONING AMPLIFIER ASSEMBLY 
    GTY784779Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    *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 air conditioning amplifier assembly connector.
    2. Measure the voltage and resistance according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Switch Condition Specified Condition
      z1-4 (B BUS) - Body ground Power switch on (IG) 11 to 14 V

      Standard Resistance

      Tester Connection Condition Specified Condition
      z1-2 (BUS G) - Body ground Always Below 1 Ω
    3. Turn the power switch on (IG).
    4. Using an oscilloscope, check the waveform.
      Item Content
      Terminal No. z1-3 (BUS) - z1-2 (BUS G)
      Tool Setting 2 V/DIV., 2 ms./DIV.
      Condition Power switch on (IG)

      OK

      Waveform is similar to that shown in the illustration.

      HINT: 

      The waveform varies with the blower speed.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE AIR CONDITIONING HARNESS ASSEMBLY. Refer to  DISASSEMBLY [10/2020 - ] 

    Result: 

    NG 

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to  REMOVAL [10/2018 - 07/2022]  , or refer to  REMOVAL [07/2022 - ] 

  4. PERFORM ACTIVE TEST USING TECHSTREAM 
    1. Perform the Active Test according to the display on the Techstream.

      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      		 Operates between 165 and 257 pulses
      A/O Servo Pulse(Rr D) No. 2 air conditioning radiator damper servo sub-assembly pulse Min.: 128
      Max.: 383      		 Operates between 158 and 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

    Result: 

    B 

    REPLACE AIR CONDITIONING HARNESS ASSEMBLY. Refer to  DISASSEMBLY [10/2020 - ] 

    Result: 

    A 

    See step  5

  5. INSPECT AIR CONDITIONING HARNESS ASSEMBLY (AIR CONDITIONING AMPLIFIER ASSEMBLY - NO. 1 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY) 
    1. Disconnect the z1 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
      z1-2 (BUS G) - A-6 (GND) Always Below 1 Ω
      z1-3 (BUS) - A-7 (LIN) Always Below 1 Ω
      z1-4 (B BUS) - A-8 (+B) Always Below 1 Ω

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE NO. 1 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY. Refer to  DISASSEMBLY [10/2020 - ] 

    Result: 

    NG 

    REPLACE AIR CONDITIONING HARNESS ASSEMBLY. Refer to  REMOVAL [10/2018 - 07/2022]  , or refer to  REMOVAL [07/2022 - ] 

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