AIR CONDITIONING SYSTEM, Diagnostic DTC:B14B8

DTC Code DTC Name
B14B8 Refrigerant Shortage

SYSTEM DESCRIPTION

This DTC is stored if the amount of refrigerant in the air conditioning system is insufficient.

The air conditioning amplifier assembly receives the ambient temperature signal, refrigerant pressure signal etc. from various sensors.

Based on these signals, the air conditioning amplifier assembly detects the amount of refrigerant.

The A/C switch indicator is turned off and air conditioning system is stopped if the amount of refrigerant is insufficient in the cycle.

DTC Code DTC Detection Condition Trouble Area
B14B8

When the following condition is detected using the refrigerant shortage check in normal operation:

The amount of refrigerant is insufficient.

  • Refrigerant

  • Refrigerant pipe line

  • Cooler expansion valve

  • Air conditioning amplifier assembly

INSPECTION PROCEDURE

Note


  • This DTC is stored when there is no refrigerant in the system, when DTC B1423, B14B8 and B1479 are output simultaneously, perform troubleshooting for DTC B14B8 first.

  • When the auxiliary battery is disconnected or the air conditioning amplifier assembly is replaced, be sure to perform servo motor initialization Click here.

  • Before disconnecting the cable form the negative (-) battery terminal or replacing the air conditioning amplifier assembly, record the last operation state of the air conditioning for each transmitter. After replacement, it is necessary to perform memory registration for each transmitter Click here.

PROCEDURE


  1. CHECK FOR AIR CONDITIONING SYSTEM LEAK


    1. Install a manifold gauge set.

    2. Recover the refrigerant from the air conditioning system using a refrigerant recovery unit.


    3. Evacuate the air conditioning system and check that vacuum can be maintained in it.

      OK
      Vacuum can be maintained in the air conditioning system.

      Tech Tips

      If vacuum cannot be maintained in the air conditioning system, refrigerant may be leaking from it. In this case, it is necessary to repair or replace the leaking part of the air conditioning system.


    NG

    REPAIR AIR CONDITIONING SYSTEM LEAK Click here

    OK

  2. CHARGE SYSTEM WITH REFRIGERANT


    1. Add an appropriate amount of refrigerant.



    NEXT

  3. CHECK FOR DTC


    1. Turn the power switch on (Ready).

    2. Check for DTCs when the following conditions are met Click here.

      Measurement Condition
      Item Condition
      A/C Switch On
      A/C operation time 15 minutes or more
      Ambient temperature* 0 to 49°C (32 to 120°F)
      Engine coolant temperature 45°C (113°F) or more

      Tech Tips


      • If the air conditioning amplifier assembly determines that the amount of refrigerant is insufficient, it may stop air conditioning system operation after 11 minutes elapse to avoid compressor burnout.

      • *: If the ambient temperature is not within the range shown, do not perform this check.

      OK
      DTC B14B8 is not output

    NG

    REPLACE COOLER EXPANSION VALVE Click here

    OK

    END (AMOUNT OF REFRIGERANT WAS DEFECTIVE)

  4. REPLACE COOLER EXPANSION VALVE


    1. Replace the cooler expansion valve with a new or known good one Click here.

      Tech Tips

      Replace the cooler expansion valve with a new or known good one because the cooler expansion valve is either stuck or clogged.


    NEXT

  5. CHARGE SYSTEM WITH REFRIGERANT


    1. Add an appropriate amount of refrigerant.



    NEXT

  6. CHECK FOR DTC


    1. Turn the power switch on (Ready).

    2. Check for DTCs when the following conditions are met Click here.

      Measurement Condition
      Item Condition
      A/C Switch On
      A/C operation time 15 minutes or more
      Ambient temperature* 0 to 49°C (32 to 120°F)
      Engine coolant temperature 45°C (113°F) or more

      Tech Tips


      • If the air conditioning amplifier assembly determines that the amount of refrigerant is insufficient, it may stop air conditioning system operation after 11 minutes elapse to avoid compressor burnout.

      • *: If the ambient temperature is not within the range shown, do not perform this check.

      OK
      DTC B14B8 is not output

    NG

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    OK

    END (COOLER EXPANSION VALVE WAS DEFECTIVE)

  7. REPAIR AIR CONDITIONING SYSTEM LEAK


    1. Identify the area where refrigerant leaks.


    2. Repair the identified area of the air conditioning system.

    3. Evacuate the air conditioning system.


    NEXT

  8. CHARGE SYSTEM WITH REFRIGERANT


    1. Add an appropriate amount of refrigerant.



    NEXT

  9. CHECK FOR DTC


    1. Turn the power switch on (Ready).

    2. Check for DTCs when the following conditions are met Click here.

      Measurement Condition
      Item Condition
      A/C Switch On
      A/C operation time 15 minutes or more
      Ambient temperature* 0 to 49°C (32 to 120°F)
      Engine coolant temperature 45°C (113°F) or more

      Tech Tips


      • If the air conditioning amplifier assembly determines that the amount of refrigerant is insufficient, it may stop air conditioning system operation after 11 minutes elapse to avoid compressor burnout.

      • *: If the ambient temperature is not within the range shown, do not perform this check.

      OK
      DTC B14B8 is not output

    NG

    REPLACE COOLER EXPANSION VALVE Click here

    OK

    END (REFRIGERANT PIPE LINE WAS DEFECTIVE)

  10. REPLACE COOLER EXPANSION VALVE


    1. Replace the cooler expansion valve with a new or known good one Click here.

      Tech Tips

      Replace the cooler expansion valve with a new or known good one because the cooler expansion valve is either stuck or clogged.


    NEXT

  11. CHARGE SYSTEM WITH REFRIGERANT


    1. Add an appropriate amount of refrigerant.



    NEXT

  12. CHECK FOR DTC


    1. Turn the power switch on (Ready).

    2. Check for DTCs when the following conditions are met Click here.

      Measurement Condition
      Item Condition
      A/C Switch On
      A/C operation time 15 minutes or more
      Ambient temperature* 0 to 49°C (32 to 120°F)
      Engine coolant temperature 45°C (113°F) or more

      Tech Tips


      • If the air conditioning amplifier assembly determines that the amount of refrigerant is insufficient, it may stop air conditioning system operation after 11 minutes elapse to avoid compressor burnout.

      • *: If the ambient temperature is not within the range shown, do not perform this check.

      OK
      DTC B14B8 is not output

    NG

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    OK

    END (COOLER EXPANSION VALVE WAS DEFECTIVE)