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AIR CONDITIONING SYSTEM(for Automatic Air Conditioning System), Diagnostic DTC:B14B3

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DTC Code DTC Name
B14B3 Lost Communication with Rear Panel LIN
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DESCRIPTION

The cooler control switch assembly communicates with the air conditioning amplifier assembly via LIN communication.

If a malfunction occurs in the LIN communication system, the air conditioning amplifier assembly will not operate, even if the cooler control switch assembly is operated.

DTC No. Detection Item DTC Detection Condition Trouble Area Memory
B14B3 Lost Communication with Rear Panel LIN Lost communication with cooler control switch assembly

  • Harness or connector

  • Cooler control switch assembly

  • Air conditioning amplifier assembly

Memorized

(10 sec. or more)*

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WIRING DIAGRAM

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CAUTION / NOTICE / HINT

Note:

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

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PROCEDURE


  1. Click here

    CHECK HARNESS AND CONNECTOR (COOLER CONTROL SWITCH ASSEMBLY - POWER SOURCE AND BODY GROUND)


    1. Disconnect the Z1 cooler control switch assembly connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      Z1-9 (+B) - Body ground Always 11 to 14 V
      Z1-1 (ACC) - Body ground Ignition switch ACC 11 to 14 V
      Z1-10 (IG+) - Body ground Ignition switch ON 11 to 14 V
      Standard Resistance
      Tester Connection Condition Specified Condition
      Z1-16 (GND) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    • OKClick here
    • NG

      REPAIR OR REPLACE HARNESS OR CONNECTOR

  2. Click here

    CHECK HARNESS AND CONNECTOR (COOLER CONTROL SWITCH ASSEMBLY - AIR CONDITIONING AMPLIFIER ASSEMBLY)


    1. Disconnect the K54 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
      Z1-13 (RLIN) - K54-14 (LIN1) Always Below 1 Ω
      Z1-13 (RLIN) or K54-14 (LIN1) - Other terminals and body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    • OKClick here
    • NG

      REPAIR OR REPLACE HARNESS OR CONNECTOR

  3. Click here

    INSPECT AIR CONDITIONING AMPLIFIER ASSEMBLY


    1. Connect the K54 air conditioning amplifier assembly connector.

    2. Turn the ignition switch to ON.

    3. Using an oscilloscope, check the waveform.

      OK
      Waveform is similar to that shown in the illustration.
      Item Content
      Terminal No. K54-14 (LIN1) - Body ground
      Tool Setting 2 V/DIV., 20 ms./DIV.
      Condition Ignition switch ON
      Result
      Proceed to
      OK
      NG

  4. *a Component with harness connected (Cooler Control Switch Assembly)
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    INSPECT AIR CONDITIONING CONTROL ASSEMBLY


    1. Connect the Z1 cooler control switch assembly connector.

    2. Turn the ignition switch to ON.

    3. Using an oscilloscope, check the waveform.

      OK
      Waveform is similar to that shown in the illustration.
      Item Content
      Terminal No. Z1-13 (RLIN) - Body ground
      Tool Setting 2 V/DIV., 20 ms./DIV.
      Condition Ignition switch ON
      Result
      Proceed to
      OK
      NG

    • OK

      REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLYClick here

    • NG

      REPLACE COOLER CONTROL SWITCH ASSEMBLYClick here