AIR CONDITIONING SYSTEM, Diagnostic DTC:B14B3

DTC Code DTC Name
B14B3 Lost Communication with Rear Panel LIN

DESCRIPTION

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

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

DTC No. DTC Detection Condition Trouble Area
B14B3 Lost communication with the cooler control switch assembly.

  • Cooler control switch assembly

  • Air conditioning amplifier assembly

  • LIN communication system

  • Harness or connector

WIRING DIAGRAM

B0018ZLE26

CAUTION / NOTICE / HINT

Note

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

PROCEDURE


  1. CHECK HARNESS AND CONNECTOR (COOLER CONTROL SWITCH ASSEMBLY - BATTERY AND BODY GROUND)


    1. B0019QXE01
      Text in Illustration
      *A for LHD
      *B for RHD
      *a

      Front view of harness connector

      (to Cooler Control Switch Assembly)

      Disconnect the cooler control switch assembly connector.

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

      Standard Resistance
      for LHD
      Tester Connection Switch Condition Specified Condition
      r1-5 (E) - Body ground Always Below 1 Ω
      for RHD
      Tester Connection Switch Condition Specified Condition
      r2-5 (E) - Body ground Always Below 1 Ω

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

      Standard Voltage
      for LHD
      Tester Connection Switch Condition Specified Condition
      r1-6 (IG+) - Body ground Engine switch off Below 1 V
      r1-6 (IG+) - Body ground Engine switch on (IG) 11 to 14 V
      for RHD
      Tester Connection Switch Condition Specified Condition
      r2-6 (IG+) - Body ground Engine switch off Below 1 V
      r2-6 (IG+) - Body ground Engine switch on (IG) 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


    1. Disconnect the r1*1 or r2*2 cooler control switch assembly connector.


      • *1: for LHD

      • *2: for RHD

    2. Disconnect the E36 air conditioning amplifier assembly connector.

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

      Standard Resistance
      for LHD
      Tester Connection Condition Specified Condition
      r1-10 (RLIN) - E36-20 (RLIN) Always Below 1 Ω
      r1-10 (RLIN) or E36-20 - Body ground Always 10 kΩ or higher
      for RHD
      Tester Connection Condition Specified Condition
      r2-10 (RLIN) - E36-20 (RLIN) Always Below 1 Ω
      r2-10 (RLIN) or E36-20 - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. CHECK COOLER CONTROL SWITCH ASSEMBLY


    1. Replace the cooler control switch assembly with new or known good one Click here.

      Tech Tips

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

      Result
      Result Proceed to
      OK (When troubleshooting according to the DTC) A
      OK (When troubleshooting according to Problem Symptoms Table) B
      NG C

    2. When troubleshooting according to the DTC:


      1. Clear the DTCs Click here.

      2. Check for DTCs Click here.

        OK
        DTC B14B3 is not output.

    3. When troubleshooting according to Problem Symptoms Table:


      1. Check that the cooler control switch assembly operation returns to normal.

        OK
        Cooler control switch assembly operation returns to normal.

    A

    END (COOLER CONTROL SWITCH ASSEMBLY WAS DEFECTIVE)

    B

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    C

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