HVAC Quiz #2

True or False, an initial vehicle inspection is a mandatory checklist during a vehicle inspection

• TRUE

• FALSE

Which statement is FALSE, initial information for vehicle inspection may consist of the following:

• Diagnostic procedures

• Wiring diagrams

• Technical service bulletins

• Date of purchase

During performing an initial diagnostic test on the A/C operation, the following are TRUE, EXCEPT:

• Pressure gauge analysis

• Level of refrigerant charge

• Leak testing – OFN, bubble, vacuum, UV dye

• Control panel LCD/graphics display

In the initial vehicle inspection, a technician might use A/C electrical tests. The electrical tests are TRUE for the statement, EXCEPT:

• Self-test checking for fault codes via control panel LCD/graphics display

• Serial test using a handheld tester – wiggle test, actuator, DTC, data logger

• Recovery

• In-depth ‘pin-by-pin’ electrical test using a break-out box or directly from the module connector

A technician may use temperature comparisons to determine whether a car’s A/C system is in good condition. Which statement is FALSE to be categorized as a temperature comparison method?

• Difference between ambient temperature and condenser temperature

• Minimum difference of 20°C between center vent temperature and the ambient temperature

• Types of refrigerants used in the system

• Difference between inlet and outlet of the evaporator

What is the MINIMUM difference in temperature that must be achieved between the centre vent temperature and the ambient temperature for a normal operation of the A/C system?

• 20°C

• 10°C

• 30°C

• 40°C

A range of 15°C to 30°C difference between the inlet and outlet of the condenser was normal. During an inspection, a technician noticed an excessive temperature difference at Abu’s condenser unit. What is the possibility of this happening to Abu’s condenser unit?

• A blockage had occurred inside the condenser

• The condenser has small leakage between the inlet and outlet

• Technician using wrong technique of diagnostic

What is the CORRECT procedure to measure temperature difference in a parallel condenser unit?

• Temperature measurements are measured from left to right or vice versa

• Temperature measurements are measured from top to bottom

Pressure gauge readings are one of the methods to diagnose an A/C system. The reading of the pressure gauge varied depending on the designated factors. From the following statement, which is FALSE factors?

• Refrigerant in system R12, R134a.

• Type of control system – FOV & TXV

• Type of compressor – fixed displacement, variable displacement.

• Ambient temperature and humidity level

A low-pressure side in an A/C system represents the amount of refrigerant metered and flowing through the evaporator and back to the compressor. What is the FALSE indication for a high-pressure side in the A/C systems accounted for?

• High-pressure side represents system load

• High-pressure side reflects the amount of heat required to be removed

• High-pressure side responsible for keeping the cabin temperature cools