Automotive Technology Chapter 49 Flashcards

Questions and Answers

A high-speed CAN BUS communicates with a scan tool through which terminal(s)?

6 and 14 (correct)

UART uses a ________ signal that toggles OV.

5 volts

Which terminal of the OBD-II data link connector is the chassis ground for all vehicles?

Which technician is correct regarding Chrysler OBD-I (1981—1995) vehicles and their BUS system?

Technician A Signup and view all the answers

The UART data BUS operates at a baud rate of ________ bps.

8192 Signup and view all the answers

Which technician is correct regarding a break-out box (BOB) and diagnostic connectors?

Both technicians Signup and view all the answers

Which of these is commonly designated D2B and connects various components in a single-ring structure?

Domestic Digital BUS Signup and view all the answers

GM Class 2 communication toggles between and volts.

0; 7 Signup and view all the answers

Which terminal of the data link connector does General Motors use for Class 2 communication?

2 Signup and view all the answers

Low-speed networks operate at less than ________ bits per second.

10,000 Signup and view all the answers

A module is also known as a ________.

Node Signup and view all the answers

Which technician is correct regarding module communications networks?

Both technicians Signup and view all the answers

Which terminal of the OBD-II data link connector is the signal ground for all vehicles?

5 Signup and view all the answers

Which of these is a version of Byteflight and is a high-speed serial communication system?

Flexray BUS Signup and view all the answers

Which of these is a single-wire serial communications protocol?

Motorola Interconnect (MI) Signup and view all the answers

Which technician is correct about a CANDi module and a twisted pair?

Technician B Signup and view all the answers

An OBD-I Ford is able to provide engine serial data if there are terminals in which cavities of the DLC?

1 and 3 Signup and view all the answers

GMLAN is the General Motors term for which type of module communication?

High-speed CAN Signup and view all the answers

Terminal 16 of the OBD-II data link connector is used for what?

12 Volts positive Signup and view all the answers

The process of sending multiple signals of information at the same time over a signal wire is called?

Multiplexing Signup and view all the answers

Why is a gateway module used?

for a scan tool data, a gateway module acts as the main communication module responsible for communicating with other modules. Signup and view all the answers

What are U codes?

U codes were at first undefined, but are now used to represent network communication related diagnostic trouble codes (DTCs). Signup and view all the answers

How do CAN H and CAN L operate?

All of the above Signup and view all the answers

Study Notes

OBD-II and Communication Protocols

High-speed CAN BUS communicates through terminals 6 and 14.
Class 2 communication in GM vehicles uses terminal 2 of the data link connector.
OBD-II uses terminal 4 for chassis ground and terminal 5 for signal ground in all vehicles.
A breakout box (BOB) accesses BUS terminals while using a scan tool; common in BMW and Mercedes with a 38-cavity diagnostic connector.

Protocols and Baud Rates

UART operates at a baud rate of 8192 bps and toggles at 5 volts.
Low-speed networks function at less than 10,000 bits per second.
Domestic Digital BUS connects multiple components in a single-ring structure with speeds up to 5,600,000 bps.

Module Communication

Chrysler OBD-I vehicles (1981-1995) utilized Serial Communications Interface (SCI), while Chrysler PCI is a three-wire protocol at terminal 2 of OBD-II.
GMLAN is General Motors' term for high-speed CAN communication.
Modules, or nodes, reduce wiring complexity and facilitate data sharing across sensors and different modules.

Signal Variations

GM Class 2 communication toggles between 0 and 7 volts.
CAN H and CAN L maintain voltage at 2.5 volts when not transmitting; CAN H rises to 3.5 volts when active.

Additional Concepts

Flexray BUS is a high-speed serial communication system and a version of Byteflight.
Motorola Interconnect (MI) is a single-wire protocol with one master and multiple slave modules.
Multiplexing allows multiple information signals to be sent simultaneously over a single wire.

Gateway Module and Diagnostic Codes

The gateway module acts as a primary communication module for scan tool data, typically found in IPC or body control modules.
U codes represent diagnostic trouble codes related to network communication, helping to identify malfunctioning modules or circuits.

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Description

Test your knowledge with flashcards focused on Chapter 49 of Automotive Technology. This chapter covers essential components of automotive communication systems including CAN BUS and UART. Perfect for aspiring automotive technicians and students in the field.