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ASE ELECTRICAL EXAM - GENERAL
ELECTRICAL/ELECTRONIC SYSTEM
DIAGNOSIS 2026 QUESTIONS AND
ANSWERS| ACE YOUR GRADES.
How does the technician communicate with the truck's various
control modules? - correct answer -By connecting a scan tool.
Where does the technician connect the scan tool? - correct
answer -A 6-pin or 9-pin data link connector is the location where
the technician connects the scan tool.
Late-model trucks will typically have a data network called
________? - correct answer -The J1939 network
How is the J1939 network effective? - correct answer -1. This
network is very effective because it can be used with up to 30
computers and communicates at very high speeds.
2.The J1939 network uses two terminating resistors that connect
in parallel with the two-wire system.
3. It is sometimes necessary for the technician to measure the
resistance of the data network at the 9-pin connector.
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4. The negative battery cable should be disconnected prior to
measuring this resistance.
What should be the correct resistance of the data network? -
correct answer -Should be approximately 60 ohms.
If this measurement is incorrect, the technician should inspect for
problems concerning the terminating resistors.
What are the problems that can occur in the bus communication?
- correct answer -Opens, shorts, and unwanted resistance.
What does diagnosing the problems in the bus communications
involve? - correct answer -Diagnosing these problems involves
using the DMM in conjunction with a diagnostic trouble chart.
Why does the scan tool become less valuable when a
communication problem occur? - correct answer -Because it will
not be able to receive data in the event of a wire failure.
Late-model trucks are equipped with several on-board computers
that control many systems. What are some examples? - correct
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answer -Examples of systems that are controlled by computers
are the: engine, transmission, antilock brakes, collision,
avoidance system, and the instrument panel.
All computers system have some key characteristics in common
with one another. What are these key characteristics? - correct
answer -1. Computers need to be connected to input devices
such as switches and sensors.
2. Computers need to have processing capability in order to
analyze the input data to determine how to react to the
information.
3. Computers also need to be connected to output to output
components in order to perform work.
What does the technician need in order to repair systems that use
computers to control their operations? - correct answer -A
technician needs to be able to communicate with the computer in
question.
What is one way to achieve communication with the computer? -
correct answer -1. Use a scan tool, which is a portable computer
that is used to retrieve codes, view live data, and run output tests
on the truck's computer systems.
ASE ELECTRICAL EXAM - GENERAL
ELECTRICAL/ELECTRONIC SYSTEM
DIAGNOSIS 2026 QUESTIONS AND
ANSWERS| ACE YOUR GRADES.
How does the technician communicate with the truck's various
control modules? - correct answer -By connecting a scan tool.
Where does the technician connect the scan tool? - correct
answer -A 6-pin or 9-pin data link connector is the location where
the technician connects the scan tool.
Late-model trucks will typically have a data network called
________? - correct answer -The J1939 network
How is the J1939 network effective? - correct answer -1. This
network is very effective because it can be used with up to 30
computers and communicates at very high speeds.
2.The J1939 network uses two terminating resistors that connect
in parallel with the two-wire system.
3. It is sometimes necessary for the technician to measure the
resistance of the data network at the 9-pin connector.
, Page | 2
4. The negative battery cable should be disconnected prior to
measuring this resistance.
What should be the correct resistance of the data network? -
correct answer -Should be approximately 60 ohms.
If this measurement is incorrect, the technician should inspect for
problems concerning the terminating resistors.
What are the problems that can occur in the bus communication?
- correct answer -Opens, shorts, and unwanted resistance.
What does diagnosing the problems in the bus communications
involve? - correct answer -Diagnosing these problems involves
using the DMM in conjunction with a diagnostic trouble chart.
Why does the scan tool become less valuable when a
communication problem occur? - correct answer -Because it will
not be able to receive data in the event of a wire failure.
Late-model trucks are equipped with several on-board computers
that control many systems. What are some examples? - correct
, Page | 3
answer -Examples of systems that are controlled by computers
are the: engine, transmission, antilock brakes, collision,
avoidance system, and the instrument panel.
All computers system have some key characteristics in common
with one another. What are these key characteristics? - correct
answer -1. Computers need to be connected to input devices
such as switches and sensors.
2. Computers need to have processing capability in order to
analyze the input data to determine how to react to the
information.
3. Computers also need to be connected to output to output
components in order to perform work.
What does the technician need in order to repair systems that use
computers to control their operations? - correct answer -A
technician needs to be able to communicate with the computer in
question.
What is one way to achieve communication with the computer? -
correct answer -1. Use a scan tool, which is a portable computer
that is used to retrieve codes, view live data, and run output tests
on the truck's computer systems.
