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 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

  • LIN communication system

  • Air conditioning control assembly

  • Air conditioning amplifier assembly

Memorized

(10 sec. or more)*

WIRING DIAGRAM

A003NRME41

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 I55 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
      I55-8 (IG+) - Body ground Power switch on (IG) 11 to 14 V
      I55-8 (IG+) - Body ground Power 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
      I55-1 (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 CONTROL ASSEMBLY - AIR CONDITIONING AMPLIFIER ASSEMBLY)


    1. Disconnect the I61 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
      I55-6 (LIN1) - I61-14 (LIN1) Always Below 1 Ω
      I55-6 (LIN1) or I61-14 (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

    A003MQ6N03

    1. Reconnect the I61 air conditioning amplifier assembly connector.

    2. Turn the power switch on (IG).

    3. Connect an oscilloscope to terminals I61-14 (LIN1) and I61-4 (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.
      Condition Power switch on (IG)
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    OK

  5. INSPECT AIR CONDITIONING CONTROL ASSEMBLY

    A003MCPC06

    1. Reconnect the I55 air conditioning control assembly connector.

    2. Turn the power switch on (IG).

    3. Connect an oscilloscope to terminals I55-6 (LIN1) and I55-1 (GND) of the air conditioning control 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.
      Condition Power switch on (IG)
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    NG

    REPLACE AIR CONDITIONING CONTROL ASSEMBLY Click here