MACS 609 CERTIFICATION EXAM QUESTIONS AND
CORRECT ANSWERS (VERIFIED ANSWERS) Q&A
2026/2027 |INSTANT DOWNLOAD PDF
1. What is the primary purpose of the MACS 609 certification
program?
A. To teach vehicle manufacturing processes
B. To verify competency in automotive air conditioning service
and safety practices
C. To certify automobile sales professionals
D. To train automotive painters
Correct Answer: B. To verify competency in automotive air
conditioning service and safety practices
Rationale: MACS certification focuses on proper servicing,
safety, environmental practices, and technical knowledge
related to mobile air conditioning systems.
2. Which refrigerant is commonly used in modern automotive
air conditioning systems?
A. R-12
B. R-22
C. R-134a
D. Ammonia
,Correct Answer: C. R-134a
Rationale: R-134a has been widely used in automotive A/C
systems as a replacement for R-12 due to environmental
regulations.
3. Which refrigerant is replacing R-134a in many newer
vehicles?
A. R-410A
B. R-1234yf
C. R-717
D. R-502
Correct Answer: B. R-1234yf
Rationale: R-1234yf has a much lower global warming potential
and is being adopted in many modern vehicles.
4. What component removes moisture from an automotive
A/C system?
A. Compressor
B. Condenser
C. Receiver-drier or accumulator
D. Evaporator
Correct Answer: C. Receiver-drier or accumulator
,Rationale: The receiver-drier or accumulator contains desiccant
material that absorbs moisture and helps protect the system.
5. What is the main function of the compressor in an A/C
system?
A. Remove heat from cabin air
B. Circulate and compress refrigerant
C. Store refrigerant
D. Filter outside air
Correct Answer: B. Circulate and compress refrigerant
Rationale: The compressor raises refrigerant pressure and
moves it through the refrigeration cycle.
6. Which component changes refrigerant from a high-pressure
vapor into a liquid?
A. Evaporator
B. Compressor
C. Condenser
D. Expansion valve
Correct Answer: C. Condenser
Rationale: The condenser releases heat and converts high-
pressure refrigerant vapor into liquid.
, 7. The evaporator’s primary function is to:
A. Absorb heat from the passenger compartment
B. Increase refrigerant pressure
C. Store refrigerant oil
D. Control compressor speed
Correct Answer: A. Absorb heat from the passenger
compartment
Rationale: Refrigerant evaporates inside the evaporator and
absorbs heat from cabin air.
8. Why must refrigerant recovery equipment be used before
opening an A/C system?
A. To increase system pressure
B. To prevent refrigerant release into the atmosphere
C. To improve cooling immediately
D. To add oil automatically
Correct Answer: B. To prevent refrigerant release into the
atmosphere
Rationale: Refrigerant must be recovered properly to protect
the environment and comply with regulations.
9. What does PAG oil provide in many automotive A/C
systems?
CORRECT ANSWERS (VERIFIED ANSWERS) Q&A
2026/2027 |INSTANT DOWNLOAD PDF
1. What is the primary purpose of the MACS 609 certification
program?
A. To teach vehicle manufacturing processes
B. To verify competency in automotive air conditioning service
and safety practices
C. To certify automobile sales professionals
D. To train automotive painters
Correct Answer: B. To verify competency in automotive air
conditioning service and safety practices
Rationale: MACS certification focuses on proper servicing,
safety, environmental practices, and technical knowledge
related to mobile air conditioning systems.
2. Which refrigerant is commonly used in modern automotive
air conditioning systems?
A. R-12
B. R-22
C. R-134a
D. Ammonia
,Correct Answer: C. R-134a
Rationale: R-134a has been widely used in automotive A/C
systems as a replacement for R-12 due to environmental
regulations.
3. Which refrigerant is replacing R-134a in many newer
vehicles?
A. R-410A
B. R-1234yf
C. R-717
D. R-502
Correct Answer: B. R-1234yf
Rationale: R-1234yf has a much lower global warming potential
and is being adopted in many modern vehicles.
4. What component removes moisture from an automotive
A/C system?
A. Compressor
B. Condenser
C. Receiver-drier or accumulator
D. Evaporator
Correct Answer: C. Receiver-drier or accumulator
,Rationale: The receiver-drier or accumulator contains desiccant
material that absorbs moisture and helps protect the system.
5. What is the main function of the compressor in an A/C
system?
A. Remove heat from cabin air
B. Circulate and compress refrigerant
C. Store refrigerant
D. Filter outside air
Correct Answer: B. Circulate and compress refrigerant
Rationale: The compressor raises refrigerant pressure and
moves it through the refrigeration cycle.
6. Which component changes refrigerant from a high-pressure
vapor into a liquid?
A. Evaporator
B. Compressor
C. Condenser
D. Expansion valve
Correct Answer: C. Condenser
Rationale: The condenser releases heat and converts high-
pressure refrigerant vapor into liquid.
, 7. The evaporator’s primary function is to:
A. Absorb heat from the passenger compartment
B. Increase refrigerant pressure
C. Store refrigerant oil
D. Control compressor speed
Correct Answer: A. Absorb heat from the passenger
compartment
Rationale: Refrigerant evaporates inside the evaporator and
absorbs heat from cabin air.
8. Why must refrigerant recovery equipment be used before
opening an A/C system?
A. To increase system pressure
B. To prevent refrigerant release into the atmosphere
C. To improve cooling immediately
D. To add oil automatically
Correct Answer: B. To prevent refrigerant release into the
atmosphere
Rationale: Refrigerant must be recovered properly to protect
the environment and comply with regulations.
9. What does PAG oil provide in many automotive A/C
systems?
