ASE HVAC EXAM PRACTICE QUESTIONS
WITH CORRECT ANSWERS 2025-2026
What would be the most likely result of a missing AC compressor clutch diode? CORRECT
ANSWER Damage to the ECM
Tech A says that the service fittings for R-134a are the same as the service fittings for R-
12. Tech B says the low-side service fitting is a 16mm quick-connect and high-side is 13mm quick-
connect. Who is right? CORRECT ANSWER Neither
An inoperative cable-
controlled heater control valve is being diagnosed. The control moves freely, but the valve does not resp
ond. Tech A says the cable housing clamp may be loose at the panel end. Tech B says the cable may be ru
sted in the housing. Who is right? CORRECT ANSWER A only
Tech A says that the scan tool receives data from the vehicle by communicating on the data bus network.
Tech B says that if one of the two data bus wires becomes broken, then the network still communicates
on the remainingYgood wire but will set a trouble code. Who is right? CORRECT ANSWER Both
The tool in the figure above is used to remove and install which AC component? CORRECT
ANSWER The Orifice tube
Referring to the figure above, the blend door gets jammed in the middle of the travel area. What is the m
ost likely system fault? CORRECT ANSWER The HVAC air temp could not be regulated.
Which AC related procedure would the above tool be used for? CORRECT
ANSWER Testing the refrigerant for impurities.
Referring to the figure above, what would the HVACYmalfunction if the component became restricted?
CORRECT ANSWER Low airflow from the ducts.
Referring to the figure above, the AC compressor clutch will not engage. Tech A says that the AC clutch re
lay could be bypassed with a fused jumper to test the load side of the circuit. Tech B says that fuse 17 sen
ds power to the AC compressor clutch relay. Who is right? CORRECT ANSWER A only
WITH CORRECT ANSWERS 2025-2026
What would be the most likely result of a missing AC compressor clutch diode? CORRECT
ANSWER Damage to the ECM
Tech A says that the service fittings for R-134a are the same as the service fittings for R-
12. Tech B says the low-side service fitting is a 16mm quick-connect and high-side is 13mm quick-
connect. Who is right? CORRECT ANSWER Neither
An inoperative cable-
controlled heater control valve is being diagnosed. The control moves freely, but the valve does not resp
ond. Tech A says the cable housing clamp may be loose at the panel end. Tech B says the cable may be ru
sted in the housing. Who is right? CORRECT ANSWER A only
Tech A says that the scan tool receives data from the vehicle by communicating on the data bus network.
Tech B says that if one of the two data bus wires becomes broken, then the network still communicates
on the remainingYgood wire but will set a trouble code. Who is right? CORRECT ANSWER Both
The tool in the figure above is used to remove and install which AC component? CORRECT
ANSWER The Orifice tube
Referring to the figure above, the blend door gets jammed in the middle of the travel area. What is the m
ost likely system fault? CORRECT ANSWER The HVAC air temp could not be regulated.
Which AC related procedure would the above tool be used for? CORRECT
ANSWER Testing the refrigerant for impurities.
Referring to the figure above, what would the HVACYmalfunction if the component became restricted?
CORRECT ANSWER Low airflow from the ducts.
Referring to the figure above, the AC compressor clutch will not engage. Tech A says that the AC clutch re
lay could be bypassed with a fused jumper to test the load side of the circuit. Tech B says that fuse 17 sen
ds power to the AC compressor clutch relay. Who is right? CORRECT ANSWER A only
