AIR CONDITIONING SYSTEM, Diagnostic DTC:B14B2

DTC Code DTC Name
B14B2 Lost Communication with Front Panel LIN

DESCRIPTION

1. for TMC, TMMR Made

The air conditioning panel (heater control switch board) communicates with the air conditioning amplifier assembly through the LIN communication system.

If the LIN communication system malfunctions, the air conditioning amplifier assembly will not operate even if the air conditioning panel (heater control switch board) is operated.

2. for TMMK Made

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

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

DTC No. DTC Detection Condition Trouble Area
B14B2

    for TMC, TMMR Made

  • Lost communication with the air conditioning panel (heater control switch board).


    for TMMK Made

  • Lost communication with the air conditioning control assembly.

    for TMC, TMMR Made

  • Harness or connector between air conditioning panel (heater control switch board) and IG circuit

  • Harness or connector between air conditioning panel (heater control switch board) and body ground

  • LIN communication system

  • Air conditioning panel (heater control switch board)

  • Air conditioning amplifier assembly


    for TMMK Made

  • Harness or connector between air conditioning control assembly and IG circuit

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

  • LIN communication system

  • Air conditioning control assembly

  • Air conditioning amplifier assembly

WIRING DIAGRAM

B000L7ZE01

INSPECTION PROCEDURE

Note

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

PROCEDURE


  1. CONFIRM MODEL

    Result
    Result Proceed to
    for TMC, TMMR Made A
    for TMMK Made B

    B

    CHECK HARNESS AND CONNECTOR (AIR CONDITIONING CONTROL ASSEMBLY - IG CIRCUIT) Click here

    A

  2. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING PANEL (HEATER CONTROL SWITCH BOARD) - IG CIRCUIT)


    1. Disconnect the I56 air conditioning panel (heater control switch board) connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      I56-2 (IG+) - Body ground Ignition switch off Below 1 V
      I56-2 (IG+) - Body ground Ignition switch ON 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING PANEL (HEATER CONTROL SWITCH BOARD) - BODY GROUND)


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

      Standard Resistance
      Tester Connection Condition Specified Condition
      I56-6 (GND) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER ASSEMBLY - AIR CONDITIONING PANEL (HEATER CONTROL SWITCH BOARD))


    1. Disconnect the I77 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
      I56-9 (LIN1) - I77-37 (LIN1) Always Below 1 Ω
      I56-9 (LIN1) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. REPLACE AIR CONDITIONING PANEL (HEATER CONTROL SWITCH BOARD)


    1. Replace the air conditioning panel (heater control switch board) Click here.

      Tech Tips

      Since the air conditioning panel (heater control switch board) cannot be inspected while it is removed from the vehicle, replace the air conditioning panel (heater control switch board) with a new or a known good one and check that the condition returns to normal.

      OK
      Air conditioning panel (heater control switch board) operation returns to normal.
      Result
      Result Proceed to
      OK A
      NG (When troubleshooting according to Problem Symptoms Table) B
      NG (When troubleshooting according to the DTC) C

    B

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here

    C

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    A

    END (HEATER CONTROL SWITCH BOARD WAS DEFECTIVE)

  6. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING CONTROL ASSEMBLY - IG CIRCUIT)


    1. Disconnect the I56 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
      I56-2 (IG+) - Body ground Ignition switch off Below 1 V
      I56-2 (IG+) - Body ground Ignition switch ON 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  7. 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
      I56-6 (GND) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


    1. Disconnect the I77 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
      I56-9 (LIN1) - I77-37 (LIN1) Always Below 1 Ω
      I56-9 (LIN1) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  9. REPLACE AIR CONDITIONING CONTROL ASSEMBLY


    1. Replace the air conditioning control assembly Click here.

      Tech Tips

      Since the air conditioning control assembly cannot be inspected while it is removed from the vehicle, replace the air conditioning control assembly with a new or a known good one and check that the condition returns to normal.

      OK
      Air conditioning control assembly operation returns to normal.
      Result
      Result Proceed to
      OK A
      NG (When troubleshooting according to Problem Symptoms Table) B
      NG (When troubleshooting according to the DTC) C

    B

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here

    C

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    A

    END (AIR CONDITIONING CONTROL ASSEMBLY WAS DEFECTIVE)