Electronic Fuel Fundamentals

Question 1

Actuator

Answer 1

An output device that receives signals from the ECM. It converts the signal into a particular action

Question 2

What is an analog signal?

Answer 2

A waveform that has a continual change in amplitude

Question 3

Digital signal

Answer 3

Is either on or off between two fixed voltages (commonly 0 to 5V with ECM circuits)

Question 4

Parameter

Answer 4

A programmable feature, value or instruction that affects vehicle operation characteristics

Question 5

Pulse width modulation

Answer 5

Occurs when a circuit is turned on and off. The width is the time that the circuit is turned on.

Question 6

What are sensors?

Answer 6

Input devices that monitor pressures, temps, levels, or mechanical movements. Sometimes are sometimes referred to as transducers

Question 7

Input devices that the operator controls are referred to as?

Answer 7

Function switches

Question 8

What does the ECM input control consist of?

Answer 8

Converters and amplifiers that modify the sensor signal.

Question 9

The process of converting analog signal to a digital signal is called?

Answer 9

Encoding

Question 10

ECM microprocessor

Answer 10

Sometimes referred to as the central processing unit (CPU). It is the brain or control section. Makes output decisions by comparing inputs to stored values and then generates outputs.

Question 11

What are the two memory systems that are most relevant?

Answer 11

RAM - random access memory

EEPROM - Electronically erasable programmable read only memory

Question 12

Multiplexing

Answer 12

A method of connecting computer controlled systems and allowing them to communicate through a common network

Question 13

The backbone

Answer 13

Is the method of connection for a network, such as wires or fibre optic cables, often referred to as the data bus. Common backbone is a twisted pair of wires that are shielded to prevent EMI

Question 14

What is baud rate?

Answer 14

The speed of data transfer over the network, commonly measured in kilo baud per second (kbps)

Question 15

What are the 3 basic functions of the warning/shut-down system?

Answer 15

Warn operator of an engine or system malfunctions
De-rate or shut-down the engine when damaging conditions exist
Generate fault codes to assist with system diagnosis

Question 16

What are the 3 levels of engine protection that can be programmed into an ECM?

Answer 16

Warning only
Warning and de-rate
Warning, de-rate and shutdown

Question 17

What are the sensor voltages used in most systems?

Answer 17

Starting from a 5V reference, return voltages from the sensors should be between 0.5V and 4.5V

Question 18

Protocol is what?

Answer 18

The common language used between control modules

Question 19

Engine manufacturer codes can be separated into what two sections?

Answer 19

Engine protection codes

System fault detection codes

Question 20

FMI?

Answer 20

Failure mode identifier

Question 21

SID

Answer 21

System identification

Question 22

PID

Answer 22

Parameter identification

Question 23

In temp sensor an open will result in what?

Answer 23

Sensor circuit voltage high

Question 24

What took is used to hook up to engines?

Answer 24

DDL diagnostic data link

Question 25

List five features of electronically controlled fuel systems?

Answer 25

1. limited or variable speed governor controls
2. multiple horsepower ratings
3. starting aid control
4. cold start and warm up mode
5. machine speed limiting
6. cruise control
7. engine warning and shutdown systems
8. self diagnostics

Question 26

Flow limiting valves are typically calibrated to shut the of the fuel to the injector when it exceeds about _____ times normal flow rate.

Answer 26

1.5 times

Question 27

Pressure limiting valve on a High Pressure Common Rail will open if the injection pressure in the rail exceed the normal max value by approximately ______ to _______.

Answer 27

2,000 psi to 3000 psi

Question 28

Depending on the system, the high pressure pup takes fuel from the low pressure system and raises it to injection pressure, which will varies from ______ to ______.

Answer 28

4,000 psi to 26,000 psi

Question 29

HEUI injectors are ________ actuated and _________ controlled.

Answer 29

hydraulically

electronically

Question 30

Injection Actuation pressure will range from approximately _______ psi to ______ psi.

Answer 30

870 psi 3,500psi

Question 31

HEUI systems operation is dependent on the interaction that occurs between four subsystems. The subsystems are?

Answer 31

electronic control
fuel transfer
hydraulic actuation
HEUI injectors

Question 32

The injection process can be broken down to four stages which are?

Answer 32

pre injection
injection
end of injection
fill

Question 33

The three main sensors monitored to control the injection process are?

Answer 33

throttle position
intake manifold pressure (turbo boost)
engine speed and timing

Question 34

What two common data link connectors?

Answer 34

J1939 nine pin deutsch connector

J1708/j1587 six pin deutsch connector