1345 Review

A restriction in the line

A cold spot or "frost ring" on an air conditioning refrigerant line is sign of:

Charged

A leak test can only be performed if the A/C system is:

Heater Core

All air entering the plenum must pass through the evaporator, therefore, the purpose of the temperature blend door is to control airflow through the:

Max A/C and Off

As a general rule, the air inlet door is only in the recirculated air position during which two modes of operation?

Condenser

Changing high pressure vapor into high pressure liquid is done at the:

When no DTC's are available

During a logical diagnostic process, when should you consult the symptom chart?

Check for compressor clutch operation

During diagnosis the refrigeration subsystem is suspected of being the cause of a symptom. Therefore, which of the following pre-checks should be performed first?

That the clutch is engaged plus the time that it is engaged

In a fixed orifice tube cycling clutch system, the total clutch cycling time is the amount of time:

Receiver/Drier

In a thermostatic expansion valve A/C system, which component retains any vapor that leaves the condenser until it becomes a liquid?

50 psi.

In general, what is the minimum refrigerant line pressure necessary to leak test a system?

Anytime the system is opened to the atmosphere

Normal evacuation/vacuum should be done:

Create the pressure differential in the system

One purpose of the fixed orifice tube is to:

Remove heat and humidity from the air

The purpose of the evaporator is to:

Evaporator Outlet

The sensing bulb of the thermostatic expansion valve is connected to the:

Thermostatic De-Icing Switch

This component is used on thermostatic expansion valve refrigeration systems to control evaporator icing.

Dual Function A/C Pressure Cut-Off Switch

This safety device increases the speed of the engine cooling fan and cut-off power to the compressor clutch when the system reaches excessive pressures.

All of the above

Under what circumstances should the suction accumulator/drier be replaced?

During Max A/C the air inlet door is in the recirc position and during Normal A/C the air inlet door is in the fresh position

What is the difference between the Max A/C and Normal A/C modes on a typical manual climate control system?

To interrupt compressor operation in the event of high system discharge pressures

What is the purpose of the single function A/C Pressure Cut-off Switch?

To prevent excessive liquid from entering the compressor

What is the purpose of the suction accumulator/drier?

YN-12 or PAG

What type of refrigerant oil should be used in an R-134a system?

Blue

When connecting the manifold gauge set, the low pressure service hose can be easily identified by the color:

Condenser, Evaporator

When constructing a basic A/C system, which two components will require a fan to improve heat transfer efficiency?

Below the area being tested

When leak testing the refrigeration system, move the leak detector slowly:

Two

When operating at medium high speed, how many resistors does current flow through on a blower switch and resistor type of circuit?

6 months

When refrigerant tracer dye is added to the refrigeration system at the factory how long will it remain useful in the system?

Lose heat

Whenever matter changes from a liquid to a vapor, it will always:

Compresser

Which component is responsible for increasing heat transfer efficiency by raising the pressure and temperature of the refrigerant entering the condenser?

Blower Motor

Which component of the heater system allows the heater core to effectively transfer heat?

Evaporator, compressor, condenser, fixed orifice tube

Which components are part of the refrigeration subsystem?

All of the above conditions must be met

Which of the conditions is part of the conditional testing requirement?

Parameter Identification Data

Which of the following are used to learn about the status of module inputs and outputs?

Blower Switch and Resistors

Which of the following blower motor circuits requires the use of a thermal limiter?

Engine running, charging with liquid refrigerant

Which of the following charging methods could cause liquid slugging at the compressor?

Air distribution doors, Fresh Air filters, and Plenum

Which of the following components are found in the air management subsystem?

Evaporator

Which of the following components should never be replaced based on the results of an electronic leak test?

SATC

Which of the following control systems automatically maintains discharge air temperature and blower speed but requires the operator to determine the discharge air location?

Ambient Air Temperature Sensor

Which of the following is a thermistor that measures the air temperature outside of the vehicle?

Checking the blower motor speed operation

Which of the following is part of the A/C system operational check?

A/C Cycling Pressure Switch

Which of the following is used on a fixed orifice tube refrigeration system to control evaporator icing?

Any of the above answers could be used

Which of the following means of identification can be used to identify an R-134a system?

Pressure is raised in the condenser and lowered in the evaporator

Which of the following occurs as the compressor forces refrigerant against the fixed orifice tube?

Defrost and Floor

Which of the following outlets will always have some airflow due to air "bleed" around the distribution doors?

Check for compressor clutch engagement

Which of the following procedures is typically done during prechecks (remember you have not yet identified a suspect subsystem)?

In-Vehicle Temperature Sensor

Which of the following sensors uses an aspirator tube to move air across the sensor?

Air Management

Which of the following subsystems route air through the heat exchangers and deliver the air to the designated nozzles, registers, or ducts?

Any of the above

Which of the following symptoms would lead you to perform a heater core pressure test?

Refrigerant line pressure

Which of the following test is used to check the operation of a thermostatic expansion valve A/C system?

Continuous Self-Test

Which of the following tests will display DTC's which are issued as a result of normal vehicle operation?