Automotive Air Conditioning Diagnosis and Repair

Auto audio on: the next questions will be read aloud when you click Continue.

1. 1

   Which A/C component raises the pressure and temperature of refrigerant vapor before it enters the condenser?

   A Compressor B Evaporator C Expansion valve
2. 2

   With the engine running and the compressor engaged, both low-side and high-side pressures are below specification and the vent air remains warm. What is the most likely cause?

   A A weak compressor that cannot create a pressure difference B An insufficient refrigerant charge C A restricted metering device with excessive high-side pressure
3. 3

   The A/C system shown cools normally while the vehicle is moving but becomes warm at idle. Which fault is most likely?

   

   A A heater control valve stuck closed B Excessive airflow across the evaporator C An inoperative condenser cooling fan
4. 4

   Why is a vacuum pump operated on an opened A/C system before refrigerant is installed?

   

   A To remove air and boil moisture out of the system B To circulate compressor oil through the system C To increase the refrigerant saturation temperature
5. 5

   In the diagram, which component is highlighted in the low-pressure line between the evaporator outlet and compressor inlet?

   

   A Expansion valve B Accumulator C Condenser
6. 6

   On a standard three-hose manifold gauge set, which hose normally connects to a vacuum pump or refrigerant service machine?

   

   A Blue hose B Red hose C Yellow center hose
7. 7

   What can an equalized static-pressure reading most reliably tell a technician after the A/C system has been off long enough to stabilize?

   A Whether system pressure is plausible for the refrigerant temperature B The exact mass of refrigerant remaining in the system C The exact amount of compressor oil present
8. 8

   When inspecting an A/C system containing ultraviolet dye, which observation is evidence of a likely refrigerant leak?

   

   A Clear condensation covering an entire cold line B A concentrated fluorescent trace around a fitting or seal C A uniform layer of dry dust on the compressor housing
9. 9

   What compressor-related measurement is the technician performing in the image?

   

   A Checking drive-belt deflection B Checking compressor pulley end play C Checking compressor clutch air gap
10. 10

    Why should a container of PAG compressor oil be capped promptly after use?

    A PAG oil is hygroscopic and absorbs moisture from the air B PAG oil rapidly turns into refrigerant when exposed to air C PAG oil becomes electrically charged when left open
11. 11

    A dual-zone climate system delivers cold air from the left vents and warm air from the right vents even though both temperatures are set equally. What is the most likely fault?

    

    A The condenser has insufficient airflow B A right-side temperature blend door or actuator is faulty C The compressor clutch air gap is too small
12. 12

    Which statement correctly describes a key service consideration for R-1234yf refrigerant?

    A It may be freely mixed with R-134a during charging B It is nonflammable under every possible condition C It is mildly flammable and requires approved, dedicated service equipment
13. 13

    After a compressor fails internally and sends metal debris through the A/C system, which repair approach is generally most appropriate?

    A Replace contaminated non-flushable components, service the drier and metering device, and flush permitted lines according to manufacturer procedures B Replace only the compressor and reuse all other components without inspection C Add extra oil to trap the debris and recharge the system