AIR CONDITIONING SYSTEM (for Automatic 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 No. DTC Detection Condition Trouble Area
B14B8

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

The amount of refrigerant is insufficient.

  • Refrigerant pipe line

  • Cooler expansion valve

  • Air conditioning amplifier assembly

INSPECTION PROCEDURE

Tech Tips

If DTC B1423 and B14B8 are output at the same time, troubleshoot for DTC B1423 first.

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 Click here.

    NEXT

  3. CHECK FOR DTC

    1. 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
      Engine condition Engine running

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

      Result
      Result Proceed to
      DTC B14B8 is output A
      DTC B14B8 is not output B
    B

    END

    A

  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 Click here.

    NEXT

  6. CHECK FOR DTC

    1. 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
      Engine condition Engine running

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

      Result
      Result Proceed to
      DTC B14B8 is output A
      DTC B14B8 is not output B
    B

    END

    A

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

  7. REPAIR AIR CONDITIONING SYSTEM LEAK

    1. Identify the area where refrigerant leaks Click here.

    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 Click here.

    NEXT

  9. CHECK FOR DTC

    1. 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
      Engine condition Engine running

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

      Result
      Result Proceed to
      DTC B14B8 is output A
      DTC B14B8 is not output B
    B

    END

    A

  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 Click here.

    NEXT

  12. CHECK FOR DTC

    1. 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
      Engine condition Engine running

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

      Result
      Result Proceed to
      DTC B14B8 is output A
      DTC B14B8 is not output B
    B

    END

    A

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here