204A - Electronic Fuel System Fundamentals Flashcards
What are some of the advantages of electronically controlled fuel injection systems?
- Optimized engine performance
- Lower exhaust emissions
- Reduced fuel consumption
- Less noise
- Improved starting
204a pg. 1
A _______ is an output device that receives electrical signals from the ECM and converts them to a particular action.
Actuator.
Solenoids, torque motors, warning lights, fuel injectors.
204a pg. 2
What electronic waveform has a continually changing amplitude?
Analog signal. Either DC or AC voltage.
204a pg. 2
What electrical signal is characterized by a switching continuous amplitude level?
Digital signal.
204a pg. 3
What is a pulse width modulation signal?
A digital signal that pulses on and off with varying width (length of on time vs. length of off time).
204a pg. 3
What are electrical input devices that monitor pressures, temperatures, fluid levels, or mechanical movements?
Sensors / Transducers
204a pg. 4
Are ECM input sensors considered passive or active devices?
Passive.
204a pg. 7
Are ECM output devices considered passive or active?
Active
204a pg. 9
Most sensors produce an ______ signal that must be converted to a ______ signal for the CPU to process.
Analog signal that must be converted to a digital signal.
204a pg. 7
What does an ECM use to provide a stable reference voltage for sensor operation?
Voltage regulator or power supply.
204a pg. 7
Is RAM volatile or non-volatile memory?
Volatile. Memory is erased when power is removed.
204a pg. 9
What type of electronic memory do most current electronic controlled fuel injector systems use?
EEPROM
204a pg. 9
What type of memory would be used to store historical fault codes that are retained if power is lost?
EEPROM
204a pg. 9
Fuel injectors, solenoids, fan clutch, relays, brake control relays, and starting aids, are examples of what ECM output device?
Actuators
204a pg. 9
What is multiplexing?
The data link between electronic control modules that allows them to communicate with each other.
204a pg. 10
How many twists should be in a multiplexing data link wire pair?
12 twists per foot
What is baud rate?
Data transfer speed
Old system (J1587 & J1708): Less than 10 kbps
New system (CAN2.0/J1939): Exceeds 250 kbps
204a pg. 10
What is a network backbone?
The method of connection. Wires, twisted pair, fibre optic, etc.
204a pg. 10
What is network protocol?
The language for data communication.
204a pg. 10
The older networking protocols J1587 & J1708 had slower speeds of how many kbps?
Less than 10kbps
204a pg. 11
The newer networking protocol CAN 2.0 / J1939 use a data transfer speed of ______
Exceeding 250 Kbps
204a pg. 11
Why are appropriate network speeds important in modern equipment?
To meet the “real time” needs of current electronic engine controls.
204a pg. 11
Older multiplexing networks were connected in _______. The whole network would become non-functional if _____.
Connected in series. The whole network would become non-functional if one part of the network failed.
204a pg. 11
The newer CAN 2.0 protocol has modules connected in ______.
A linear or single track arrangement. If one module fails, the rest of the network remains functional.
204a pg. 12