Question 1

What field in a data packet is used to define the urgency of a broadcast over the data bus?

Accepted Answer

The arbitration field in a data packet is used to determine the priority of the message, thus defining the urgency of a broadcast over the data bus.

Question 2

What color is assigned to the physical power line carrier (PLC)communication between a tractor and trailer?

Accepted Answer

B

Question 3

What universal standards are used to ensure that control module interconnectivity on J1939 adheres to both national and international standards?

Accepted Answer

ISO 9141 and ISO 11898 are standards related to vehicle communication systems, ensuring compatibility and interoperability of control modules in vehicles, including those using the J1939 protocol. ISO 9141 is related to the diagnostic systems, while ISO 11898 specifies the requirements for Controller Area Network (CAN) communication.

Question 4

Which of the following methods are used to access diagnostic codes from a controller with an address on a truck data bus?

Accepted Answer

All of the methods listed (flash codes, PC-based Electronic Service Tools (EST), and generic Hand-Held Electronic Service Tools (HH-EST)) are used to access diagnostic codes from controllers on a truck data bus.

Question 5

Technician A says that if one module networked to a J1939 data bus fails,it should not affect the operation of other modules on the bus.Technician B says that an advantage of using a data bus,is that controllers on the bus can share input signals from key components such as a TPS.Who is correct?

Accepted Answer

The J1939 data bus is designed to allow modules to operate independently, so if one fails, it should not affect the operation of others. Additionally, a key advantage of using a data bus is indeed the ability for controllers to share input signals from components like the Throttle Position Sensor (TPS), making the system more efficient.

Question 6

Technician A says that a black J1939 9-pin DLC can be connected to a green J1939 9-pin receptacle.Technician B says that a green J1939 9-pin DLC can be connected to a black J1939 9-pin receptacle.Who is correct?

Accepted Answer

The answer of Technician A says that a black J1939...

Question 7

On a truck data bus,how many wires are used to broadcast J1939 message packets?

Accepted Answer

J1939 messages are broadcast over a Controller Area Network (CAN) bus, which typically uses a two-wire differential signal to communicate.

Question 8

What is another way of saying algorithm in a vehicle computer processing cycle?

Accepted Answer

Mapping is often used in the context of algorithms within vehicle computer processing cycles, referring to the way data or instructions are organized and processed to achieve a specific outcome, similar to how an algorithm functions.

Question 9

How does power line carrier (PLC)trailer-to-tractor multiplexing transmit messages?

Accepted Answer

PLC trailer-to-tractor multiplexing transmits messages by superimposing radio frequency signals over the existing 12-volt auxiliary wire, allowing for communication without the need for additional dedicated wiring.

Question 10

Which source address (SA/MID)code identifies the address of the transmission electronics on a truck data bus?

Accepted Answer

The answer of Which source address (SA/MID)code identifies the address...

Question 11

Three of the following mean the same thing.Which is the odd one out?

Accepted Answer

The odd one out is "Internet" because it refers to the global network of interconnected computers and servers allowing for data exchange worldwide, while the others (data bus, neural network, and multiplex backbone) relate to specific components or concepts within computer architecture and data processing, not to a global network.

Question 12

Technician A says that most trucks that use a J1939 data bus have provision for the older J1587/1708 data bus.Technician B says that the current J1939 data bus is based on CAN 2.0 communications protocols.Who is correct?

Accepted Answer

Both statements are correct. Many trucks designed to use the J1939 data bus also include provisions for the older J1587/1708 data bus to ensure compatibility with older diagnostic equipment and systems. The J1939 data bus is indeed based on the Controller Area Network (CAN) 2.0 communication protocols, which is a standard designed to allow microcontrollers and devices to communicate with each other within a vehicle without a host computer.

Question 13

Which of the controllers is 'in charge' of managing data on a truck J1939 data bus?

Accepted Answer

In a J1939 data bus system, the bus topology is designed in such a way that no single controller is 'in charge' of managing data. Instead, all controllers communicate over a shared network, allowing for decentralized control and data sharing among multiple systems.

Question 14

What is the current automotive/ light-duty truck equivalent of the J1939 data bus used on medium/heavy trucks on passenger cars and light duty trucks?

Accepted Answer

CAN-C is the equivalent of the J1939 data bus used on passenger cars and light-duty trucks, providing a high-speed communication network for vehicle systems.

Question 15

What type of data connector is required to access a SAE J1939 data bus?

Accepted Answer

SAE J1939 data buses can be accessed using 9-pin black Deutsch, 9-pin green Deutsch, or J1962 connectors.

Question 16

Which of the following are advantages of a multiplexed truck chassis?

Accepted Answer

Multiplexed truck chassis systems reduce the need for extensive hard wiring and input hardware by allowing multiple signals to be transmitted over a single data bus. This also facilitates information sharing between different controllers, enhancing system efficiency and integration.

Question 17

What is the advantage of using serial data transmission on a current truck data bus as compared with a multiple track (parallel)model?

Accepted Answer

Serial data transmission typically has lower failure rates compared to parallel transmission because it reduces the complexity of wiring and minimizes issues like crosstalk and signal degradation.

Question 18

Which of the following is another way of saying data bus communications?

Accepted Answer

Multiplexing is a method used in data bus communications to send multiple signals or streams of information over a communication link at the same time in the form of a single, complex signal; then, at the receiving end, the complex signal is separated back into its individual signals. This is a fundamental concept in data bus communications, where multiple data signals are transmitted across the same data bus.

Question 19

What type of data connector is associated with the SAE J1587/1708 data bus?

Accepted Answer

The SAE J1587/1708 data bus typically uses a 6-pin Deutsch connector for its physical connection.

Question 20

When power line carrier (PLC)multiplexing is used,what vehicle system is it associated with?

Accepted Answer

Power Line Carrier (PLC) multiplexing is primarily associated with trailer ABS (Anti-lock Braking Systems). This technology allows for communication over the power lines that connect a vehicle to its trailer, enabling the transmission of ABS signals without the need for additional dedicated wiring.

Quiz 12: Multiplexing