AIR CONDITIONING SYSTEM(for Manual Air Conditioning System), 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 a malfunction occurs in the LIN communication system, the air conditioning amplifier assembly will 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

  • Air conditioning control assembly

  • Air conditioning amplifier assembly

Memorized

(10 sec. or more)*


WIRING DIAGRAM

B00892CE54

PROCEDURE


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


    1. Disconnect the K26 air conditioning control assembly connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      K26-2 (IG+) - Body ground Ignition switch ON 11 to 14 V
      K26-2 (IG+) - Body ground Ignition switch off Below 1 V
      Result
      Proceed to
      OK
      NG

    NG
    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
      K26-6 (GND) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG
    OK
  3. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING CONTROL 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
      K26-9 (LIN1) - K54-14 (LIN1) Always Below 1 Ω
      K26-9 (LIN1) or K54-14 (LIN1) - Other terminals and body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG
    OK
  4. INSPECT AIR CONDITIONING AMPLIFIER ASSEMBLY

    B00848GN03

    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

    NG
    OK
  5. INSPECT AIR CONDITIONING CONTROL ASSEMBLY

    B0087AWE01

    1. Connect the K26 air conditioning control 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. K26-9 (LIN1) - Body ground
      Tool Setting 2 V/DIV., 20 ms./DIV.
      Condition Ignition switch ON
      Result
      Proceed to
      OK
      NG

    OK
    NG