Deck 11: Apadsacpu Air Conditioning Control Systems Air Conditioning Protection Unit

Question 1

An APAD CM-813 module does not receive input information from:

A) The high pressure switch
B) The low pressure switch
C) The ECM fan relay
D) The cab thermostat

Answer 1

C

Question 2

An APAD CM-813 module does not deliver output signals to:

A) The air conditioning compressor clutch
B) The fan (fan actuator)
C) The evaporator fan
D) The diagnostic LED's

Answer 2

C

Question 3

What is the possible cause for a dash message "No RPM message"?

A) Engine RPM's are less than 600
B) Engine RPM's are less than 500
C) Engine RPM's are less than 400
D) Engine RPM's are less than 300

Answer 3

D

Question 4

Which of the following could cause low pressure fault?

A) Cold ambient temperature
B) Loss of refrigerant
C) Blockage in the evaporator
D) All of the above could cause a low pressure fault

Question 5

APAD or ACPU systems are designed to reduce maintenance costs associated with the HVAC system by:

A) Controlling thermostat operation
B) Controlling compressor operation
C) Controlling thermostatic expansion valve operation
D) Controlling receiver drier operation

Question 6

How does the APAD and ACPU system lubricate the compressor and components all year long?

A) They inject oil into the compressor inlet.
B) They engage the compressor for 15 seconds after start up.
C) They prevent the compressor from engaging in cold weather to keep all the oil within the compressor.
D) APAD and ACPU's have nothing to do with the lubrication of compressors or system components.

Question 7

An air conditioning system battery voltage low fault indicates a voltage drop below:

A) 12 volts
B) 11 volts
C) 10 volts
D) 9 volts

Question 8

If you got a dash message "A/C SYST CLUTCH CIR SHORT" which component would you test?

A) The wiring to the high pressure switch
B) The compressor ground circuit
C) The clutch coil
D) The clutch drive pulley

Question 9

Which of the following would NOT cause a low voltage fault?

A) Defective charging system
B) Excessive electrical loads
C) High refrigerant pressure
D) Discharged or defective batteries

Question 10

APAD and ACPU relieves stress on the engine starting system by not allowing the compressor clutch to engage until the engine has been running for:

A) 5 seconds
B) 10 seconds
C) 15 seconds
D) 20 seconds

Question 11

Which of the following would NOT cause a high pressure switch open fault?

A) A break in the wiring harness
B) An unseated connector
C) Refrigerant overcharge
D) Moisture intrusion into the connectors or switch

Question 12

A dash message "low air" and the air conditioning compressor not engaging indicates the system air pressure is below:

A) 90 PSI
B) 80 PSI
C) 70 PSI
D) 60 PSI

Question 13

Which of the following would NOT cause a high pressure fault?

A) Fan drive failure
B) Evaporator blockage
C) Condenser blockage
D) Refrigerant overcharge

Question 14

Which of the following could cause a fault code erratic TStat?

A) Faulty thermostat
B) Faulty A/C ON switch
C) Intermittent connections in the wiring harness or connector
D) Any of the above could trigger an erratic TStat code

Question 15

How are blink codes cleared from a CM-813 module?

A) Cycling the ignition switch 1 second on 1 second off for four consecutive cycles
B) Removing the negative ground cable from the vehicle battery
C) Self-clearing depending on how persistent the fault is
D) Both A and C are methods of clearing fault codes