VEHICLE COMMUNICATION NETWORKS
- QUESTIONS AND ANSWERS | 2026
UPDATE | 100% CORRECT.
Part 1: Fundamentals & Network Classification
Q1. Which company originally developed the Controller Area
Network (CAN) protocol?
A. Siemens
B. Motorola
C. Bosch
D. Intel
Answer: C
Rationale: CAN was developed by Robert Bosch GmbH in the 1980s and
officially released in 1986. It was designed for in-vehicle communication
between electronic control units (ECUs) without a host computer. Siemens,
Motorola, and Intel were involved in semiconductor manufacturing but did
not create the protocol itself .
Q2. In automotive network classification, which bus system is the
typical representative of a Class A network?
A. CAN Bus
B. LIN Bus
C. MOST Bus
D. FlexRay Bus
Answer: B
Rationale: Class A networks are low-speed (typically <10 kbit/s), low-cost
systems used for body electronics. LIN (Local Interconnect Network) is
the classic Class A example, designed for simple devices like window lifts,
seat controls, and mirrors. CAN is Class B/C, MOST and FlexRay are higher-
speed networks for multimedia and safety systems .
,Q3. Which vehicle network protocol uses fiber optic cables as its
primary transmission medium?
A. CAN
B. LIN
C. MOST
D. FlexRay
Answer: C
Rationale: MOST (Media Oriented Systems Transport) uses plastic
optical fiber (POF) to transmit data via light signals. This provides high
bandwidth (up to 150 Mbit/s in recent versions) and immunity to
electromagnetic interference, making it ideal for infotainment and
multimedia systems .
Q4. What is the function of a gateway in a vehicle's network
architecture?
A. To amplify signals on the CAN bus
B. To convert analog sensor signals to digital
C. To enable communication between different network protocols and speeds
D. To store diagnostic trouble codes
Answer: C
Rationale: A gateway acts as a translator between different bus systems
(e.g., CAN, LIN, FlexRay, Ethernet) that operate at different speeds and use
different protocols. It allows a diagnostic tool connected to a high-speed CAN
to access data from a low-speed LIN network. Without a gateway, these
different networks cannot communicate directly .
Q5. In the context of vehicle networking, what does the acronym
"ECU" stand for?
A. Engine Cooling Unit
B. Electronic Control Unit
, C. Energy Conversion Unit
D. Emissions Calibration Unit
Answer: B
Rationale: An Electronic Control Unit is any embedded system in
automotive electronics that controls one or more electrical systems or
subsystems (e.g., Engine Control Module, Transmission Control Module, Body
Control Module) .
Part 2: CAN Bus (Controller Area Network)
Q6. What is the maximum data transmission rate of a standard high-
speed CAN bus?
A. 20 kbit/s
B. 125 kbit/s
C. 1 Mbit/s
D. 10 Mbit/s
Answer: C
Rationale: ISO 11898-2 standard for high-speed CAN specifies a maximum
bit rate of 1 Mbit/s at a maximum bus length of 40 meters. Low-speed CAN
(fault-tolerant) operates at up to 125 kbit/s .
Q7. For a high-speed CAN bus operating at 500 kbit/s, what is the
theoretical CAN-High (dominant) voltage?
A. 1.5 V
B. 2.5 V
C. 3.5 V
D. 5.0 V
Answer: C
Rationale: On a high-speed CAN bus:
Recessive state: Both CAN-High and CAN-Low sit at
approximately 2.5 V.
- QUESTIONS AND ANSWERS | 2026
UPDATE | 100% CORRECT.
Part 1: Fundamentals & Network Classification
Q1. Which company originally developed the Controller Area
Network (CAN) protocol?
A. Siemens
B. Motorola
C. Bosch
D. Intel
Answer: C
Rationale: CAN was developed by Robert Bosch GmbH in the 1980s and
officially released in 1986. It was designed for in-vehicle communication
between electronic control units (ECUs) without a host computer. Siemens,
Motorola, and Intel were involved in semiconductor manufacturing but did
not create the protocol itself .
Q2. In automotive network classification, which bus system is the
typical representative of a Class A network?
A. CAN Bus
B. LIN Bus
C. MOST Bus
D. FlexRay Bus
Answer: B
Rationale: Class A networks are low-speed (typically <10 kbit/s), low-cost
systems used for body electronics. LIN (Local Interconnect Network) is
the classic Class A example, designed for simple devices like window lifts,
seat controls, and mirrors. CAN is Class B/C, MOST and FlexRay are higher-
speed networks for multimedia and safety systems .
,Q3. Which vehicle network protocol uses fiber optic cables as its
primary transmission medium?
A. CAN
B. LIN
C. MOST
D. FlexRay
Answer: C
Rationale: MOST (Media Oriented Systems Transport) uses plastic
optical fiber (POF) to transmit data via light signals. This provides high
bandwidth (up to 150 Mbit/s in recent versions) and immunity to
electromagnetic interference, making it ideal for infotainment and
multimedia systems .
Q4. What is the function of a gateway in a vehicle's network
architecture?
A. To amplify signals on the CAN bus
B. To convert analog sensor signals to digital
C. To enable communication between different network protocols and speeds
D. To store diagnostic trouble codes
Answer: C
Rationale: A gateway acts as a translator between different bus systems
(e.g., CAN, LIN, FlexRay, Ethernet) that operate at different speeds and use
different protocols. It allows a diagnostic tool connected to a high-speed CAN
to access data from a low-speed LIN network. Without a gateway, these
different networks cannot communicate directly .
Q5. In the context of vehicle networking, what does the acronym
"ECU" stand for?
A. Engine Cooling Unit
B. Electronic Control Unit
, C. Energy Conversion Unit
D. Emissions Calibration Unit
Answer: B
Rationale: An Electronic Control Unit is any embedded system in
automotive electronics that controls one or more electrical systems or
subsystems (e.g., Engine Control Module, Transmission Control Module, Body
Control Module) .
Part 2: CAN Bus (Controller Area Network)
Q6. What is the maximum data transmission rate of a standard high-
speed CAN bus?
A. 20 kbit/s
B. 125 kbit/s
C. 1 Mbit/s
D. 10 Mbit/s
Answer: C
Rationale: ISO 11898-2 standard for high-speed CAN specifies a maximum
bit rate of 1 Mbit/s at a maximum bus length of 40 meters. Low-speed CAN
(fault-tolerant) operates at up to 125 kbit/s .
Q7. For a high-speed CAN bus operating at 500 kbit/s, what is the
theoretical CAN-High (dominant) voltage?
A. 1.5 V
B. 2.5 V
C. 3.5 V
D. 5.0 V
Answer: C
Rationale: On a high-speed CAN bus:
Recessive state: Both CAN-High and CAN-Low sit at
approximately 2.5 V.
