AIR CONDITIONING SYSTEM(for Automatic Air Conditioning System with Side-mounted Air Conditioner Pressure Sensor), Diagnostic DTC:B14B2

DTC Code DTC Name
B14B2 Lost Communication with Front Panel LIN

DESCRIPTION

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

If the LIN communication system malfunctions, the air conditioning amplifier assembly does not operate even if the air conditioning control assembly is operated.

DTC No. Detection Item DTC Detection Condition Trouble Area Memory
B14B2 Lost Communication with Front Panel LIN Lost communication with air conditioning control assembly

  • Harness or connector between air conditioning control assembly and IG power source

  • Harness or connector between air conditioning control assembly and body ground

  • LIN communication system

  • Air conditioning control assembly

  • Air conditioning amplifier assembly

Memorized

(10 seconds or more)*

WIRING DIAGRAM

A001UMWE42

CAUTION / NOTICE / HINT

Note

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

PROCEDURE


  1. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING CONTROL ASSEMBLY - IG POWER SOURCE)


    1. Disconnect the F61 air conditioning control assembly connector.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      F61-10 (IG+) - Body ground Ignition switch ON 11 to 14 V
      F61-10 (IG+) - Body ground Ignition switch off Below 1 V
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


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

      Standard Resistance
      Tester Connection Condition Specified Condition
      F61-16 (GND) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER ASSEMBLY - AIR CONDITIONING CONTROL ASSEMBLY)


    1. Disconnect the F73 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
      F61-2 (LIN1) - F73-14 (LIN1) Always Below 1 Ω
      F61-2 (LIN1) or F73-14 (LIN1) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. INSPECT AIR CONDITIONING AMPLIFIER ASSEMBLY


    1. Reconnect the F73 air conditioning amplifier assembly connector.

    2. Turn the ignition switch to ON.

    3. A001UVYE03

      Connect an oscilloscope to terminals F73-14 (LIN1) and F73-4 (GND) of the air conditioning amplifier assembly and check the waveform.

      OK
      Waveform is similar to that shown in the illustration.
      Item Content
      Tool Setting 2 V/DIV., 20 ms./DIV.
      Vehicle Condition Ignition switch ON
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    OK

  5. INSPECT AIR CONDITIONING CONTROL ASSEMBLY


    1. Reconnect the F61 air conditioning control assembly connector.

    2. Turn the ignition switch to ON.

    3. Connect an oscilloscope to terminals F61-2 (LIN1) and F61-16 (GND) of the air conditioning control assembly and check the waveform.

      A001UXTC03
      *a

      Component with harness connected

      (Air Conditioning Control Assembly)

      		 - -
      OK
      Waveform is similar to that shown in the illustration.
      Item Content
      Tool Setting 2 V/DIV., 20 ms./DIV.
      Vehicle Condition Ignition switch to ON
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    NG

    REPLACE AIR CONDITIONING CONTROL ASSEMBLY Click here