ASE A/C EXAM QUESTIONS AND
ANSWERS WITH SOLUTIONS 2024
An EATC air conditioning system has low fan speed operation during high demand situations, like in
direct sunlight. Technician A says this is because something is covering the sun load sensor's photo
diode. Technician B says a sun load sensor is a variable resistor and can be tested with an ohmmeter.
Who is correct? - ANSWER Both A and B
A gurgling sound is heard coming from inside the dashboard of a vehicle. Technician A says this is air
trapped in the heater core. Technician B says this noise can be caused by a blown head gasket. Who is
correct? - ANSWER Both A and B
A manifold gauge indicates a system has low discharge pressure. The MOST likely cause of this condition
is: - ANSWER A damaged compressor reed valve.
The compressor is rapidly cycling on and off on a CCOT (cycling clutch orifice tube) air conditioning
system. Technician A says this condition can be caused by a low refrigerant charge. Technician B says this
could be caused by a faulty clutch cycling switch. Who is correct? - ANSWER Both A and B
Technician A says while performing a retrofit from R-12 refrigerant to R134a refrigerant, the refrigerant
must be recovered into a dedicated cylinder, they cannot be mixed. Technician B says R-12 refrigerant
functions at higher pressures than R-134a refrigerant does. Who is correct? - ANSWER Tech A
Technician A says an ambient temperature sensor senses cabin air temperature. Technician B says a
faulty ambient temperature sensor can prevent compressor clutch engagement. Who is correct? -
ANSWER Tech B
During an initial inspection, the technician notices that one line on the receiver drier is cooler than the
other. This is caused by: - ANSWER A restriction in the receiver drier.
During a performance test on a CCOT system the manifold gauge indicates that the high side pressure is
low and the low side pressure is high. This is caused by a: - ANSWER Faulty compressor
, An air conditioning system blows only warm air when the heater is on high output. Technician A says this
could be a faulty heater control valve. Technician B says this could be caused by the cooling system's
thermostat. Who is correct? - ANSWER Both A and B
Technician A says a fixed orifice tube varies the flow of refrigerant in relation to temperature. Technician
B says a fixed orifice tube is located between the condenser and the evaporator. Who is correct? -
ANSWER B Only (A fixed orifice tube provides a consistent output, based upon the size of its orifice. It's a
compromise between idle and highway conditions)
Technician A says the expansion valve is located on the inlet port of the evaporator. Technician B says the
expansion valve's temperature sensing bulb is located near the outlet port of the evaporator. Who is
correct? - ANSWER Both A and B
During a visual inspection an oily spot is found on a hose leading from the compressor. Technician A says
there may be a refrigerant leak in the system. Technician B says today's R134a systems use mineral oil
instead of the older R12 compatible PAG oil. Who is correct? - ANSWER Tech A Only
An air conditioning system contains a thermostatic expansion valve. The suction line leading to the
compressor is cool to the touch. This indicates: - ANSWER Normal Condition
All of these are true about an accumulator EXCEPT: - ANSWER This system contains a thermostatic
expansion valve to meter the refrigerant.
A vehicle has poor air conditioning performance. The customer has added R134a refrigerant to the
system. Technician A says to use a refrigerant identifier. Technician B says refrigerant mixtures are not
recommended, but will not affect system pressures. Who is correct? - ANSWER Tech A Only
Two technicians are discussing a CCOT air conditioning system. Technician A says the system's pressure
cycling clutch switch contains a bulb placed on the inlet port of the evaporator core. Technician B says a
pressure cycling switch is located on the low side of the system. Who is correct? - ANSWER Tech B Only
All these statements are true about a throttle position sensor EXCEPT: - ANSWER The ECM disengages
the A/C clutch at idle.
(The compressor's clutch is not disengaged at idle, it's disengaged at WOT providing additional power
when needed)
ANSWERS WITH SOLUTIONS 2024
An EATC air conditioning system has low fan speed operation during high demand situations, like in
direct sunlight. Technician A says this is because something is covering the sun load sensor's photo
diode. Technician B says a sun load sensor is a variable resistor and can be tested with an ohmmeter.
Who is correct? - ANSWER Both A and B
A gurgling sound is heard coming from inside the dashboard of a vehicle. Technician A says this is air
trapped in the heater core. Technician B says this noise can be caused by a blown head gasket. Who is
correct? - ANSWER Both A and B
A manifold gauge indicates a system has low discharge pressure. The MOST likely cause of this condition
is: - ANSWER A damaged compressor reed valve.
The compressor is rapidly cycling on and off on a CCOT (cycling clutch orifice tube) air conditioning
system. Technician A says this condition can be caused by a low refrigerant charge. Technician B says this
could be caused by a faulty clutch cycling switch. Who is correct? - ANSWER Both A and B
Technician A says while performing a retrofit from R-12 refrigerant to R134a refrigerant, the refrigerant
must be recovered into a dedicated cylinder, they cannot be mixed. Technician B says R-12 refrigerant
functions at higher pressures than R-134a refrigerant does. Who is correct? - ANSWER Tech A
Technician A says an ambient temperature sensor senses cabin air temperature. Technician B says a
faulty ambient temperature sensor can prevent compressor clutch engagement. Who is correct? -
ANSWER Tech B
During an initial inspection, the technician notices that one line on the receiver drier is cooler than the
other. This is caused by: - ANSWER A restriction in the receiver drier.
During a performance test on a CCOT system the manifold gauge indicates that the high side pressure is
low and the low side pressure is high. This is caused by a: - ANSWER Faulty compressor
, An air conditioning system blows only warm air when the heater is on high output. Technician A says this
could be a faulty heater control valve. Technician B says this could be caused by the cooling system's
thermostat. Who is correct? - ANSWER Both A and B
Technician A says a fixed orifice tube varies the flow of refrigerant in relation to temperature. Technician
B says a fixed orifice tube is located between the condenser and the evaporator. Who is correct? -
ANSWER B Only (A fixed orifice tube provides a consistent output, based upon the size of its orifice. It's a
compromise between idle and highway conditions)
Technician A says the expansion valve is located on the inlet port of the evaporator. Technician B says the
expansion valve's temperature sensing bulb is located near the outlet port of the evaporator. Who is
correct? - ANSWER Both A and B
During a visual inspection an oily spot is found on a hose leading from the compressor. Technician A says
there may be a refrigerant leak in the system. Technician B says today's R134a systems use mineral oil
instead of the older R12 compatible PAG oil. Who is correct? - ANSWER Tech A Only
An air conditioning system contains a thermostatic expansion valve. The suction line leading to the
compressor is cool to the touch. This indicates: - ANSWER Normal Condition
All of these are true about an accumulator EXCEPT: - ANSWER This system contains a thermostatic
expansion valve to meter the refrigerant.
A vehicle has poor air conditioning performance. The customer has added R134a refrigerant to the
system. Technician A says to use a refrigerant identifier. Technician B says refrigerant mixtures are not
recommended, but will not affect system pressures. Who is correct? - ANSWER Tech A Only
Two technicians are discussing a CCOT air conditioning system. Technician A says the system's pressure
cycling clutch switch contains a bulb placed on the inlet port of the evaporator core. Technician B says a
pressure cycling switch is located on the low side of the system. Who is correct? - ANSWER Tech B Only
All these statements are true about a throttle position sensor EXCEPT: - ANSWER The ECM disengages
the A/C clutch at idle.
(The compressor's clutch is not disengaged at idle, it's disengaged at WOT providing additional power
when needed)
