Question 1

Which was the first computer controlled, truck diesel engine to be manufactured in North America?
A) DDC Series 92 DDEC I
B) DDC Series 50
C) DDC Series 60
D) DDC Series 40

Accepted Answer

The DDC Series 92 DDEC I was the first computer controlled, truck diesel engine to be manufactured in North America.

Question 2

What engine was the first generation of DDEC electronics (DDEC I) used on?
A) Series 92
B) 60 Series
C) 55 Series
D) 50 Series

Accepted Answer

DDEC I was first introduced on the Series 92 engines by Detroit Diesel.

Question 3

In what MY did single actuator EUIs cease to be used on any North American, Highway certified diesel engine?
A) 1997
B) 2003
C) 2007
D) 2010

Accepted Answer

D

Question 4

Which of the following types of throttle position sensors (TPS) would be used on most diesel engines fueled by single actuator EUIs?
A) Potentiometer
B) Variable Capacitance
C) Hall-effect
D) Acoustic

Accepted Answer

Potentiometer-type TPS is commonly used in diesel engines with single actuator Electronic Unit Injectors (EUIs) because it provides a variable resistance based on the throttle position, which is easily interpreted by the engine's electronic control unit to adjust fuel injection.

Question 5

Which of the following is NOT true of the signal voltage value returned by a potentiometer type TPS if it is functioning properly?
A) varies proportionally with pedal travel
B) must be less than V-Ref value
C) lowest value is at zero pedal travel
D) digital PWM format

Accepted Answer

A properly functioning potentiometer type Throttle Position Sensor (TPS) returns an analog voltage signal, not a digital Pulse Width Modulation (PWM) format. The signal varies proportionally with the pedal travel, must be less than the reference voltage (V-Ref), and its lowest value corresponds to zero pedal travel.

Question 6

How is EUI duty cycle usually displayed on electronic service tools (ESTs)?
A) crank angle degrees
B) pulse width (PW)
C) on-off duration
D) cubic mm of fuel pumped

Accepted Answer

The EUI duty cycle is typically displayed as pulse width (PW) on electronic service tools, indicating the duration of the electrical signal sent to the injector.

Question 7

What force is used to convert charging pressures into injection pressures in EUIs?
A) electronic from control cartridge
B) electrical from injector drivers
C) hydraulic from fuel sub-system
D) mechanical from injector cam profile

Accepted Answer

The mechanical force from the injector cam profile is used to convert charging pressures into injection pressures in Electronic Unit Injectors (EUIs).

Question 8

What mechanical feature defines the limits within which EUI fuel pulse width (PW) must take place?
A) injector cam profile
B) camshaft position signal
C) valve cam profiles
D) crankshaft position signal

Accepted Answer

The injector cam profile defines the mechanical limits for the EUI fuel pulse width, as it controls the timing and duration of the injection event.

Question 9

Which of the following terms used by DDC to describe DDEC EUI fueling has the same meaning as split shot injection?
A) pilot injection
B) detonation
C) quiescent combustion
D) maximizing injection pressure

Accepted Answer

Pilot injection, also known as split shot injection, involves injecting a small amount of fuel before the main injection event to initiate combustion more smoothly, reduce noise, and lower emissions.

Question 10

When a typical EUI is managing pilot injection, when should the second pulse begin?
A) at 15 degrees ATDC
B) the moment the pilot pulse ignites
C) peak cylinder pressure
D) during afterburn

Accepted Answer

The second pulse in a typical EUI (Electronic Unit Injector) system managing pilot injection should begin the moment the pilot pulse ignites. This timing helps in achieving a more efficient combustion process by preparing the cylinder for the main injection event.

Question 11

Which of the following is NOT an advantage of pilot injection?
A) reduced engine wear
B) lower cold-start emissions
C) detonation avoidance
D) extended EUI service life

Accepted Answer

Pilot injection primarily helps in reducing engine wear, lowering cold-start emissions, and avoiding detonation. It does not directly contribute to extending the service life of the Electronic Unit Injector (EUI).

Question 12

What does the injector response time (IRT) allow DDEC electronics to do when managing EUI pulse width?
A) compensate for minor EUI circuit resistances
B) adjust for EUI mechanical wear
C) compensate for a failed EUI control cartridge
D) adjust EUI firing sequence

Accepted Answer

The injector response time (IRT) allows DDEC electronics to compensate for minor EUI circuit resistances, ensuring accurate fuel delivery by adjusting the pulse width accordingly.

Question 13

When a single-cylinder cutout test is being performed on a typical EUI-fueled engine with the objective of identifying a dead cylinder, what happens to mean (average) PW when the EUI over the dead cylinder is cut?
A) mean PW increases
B) mean PW does not change
C) mean PW decreases
D) engine rpm drops by approximately 17 %

Accepted Answer

The answer of When a single-cylinder cutout test is being...

Question 14

What electronic component houses the electronic distributor unit (EDU) in versions of DDEC fueled engines manufactured before 2007?
A) ECM
B) PCM
C) MCM
D) CPC

Accepted Answer

The Electronic Control Module (ECM) houses the Electronic Distributor Unit (EDU) in versions of DDEC fueled engines manufactured before 2007. The ECM is responsible for controlling the engine's fuel injection and ignition systems, among other functions.

Question 15

A Series 60 engine equipped with N2 injectors is being tuned up using the DDC service literature procedure. Technician A says that when the valves at cylinder #4 are at overlap, the EUI height may be set at cylinder #6. Technician B says that in this position, the valves at cylinder #3 may also be set. Who is correct?
A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Accepted Answer

In a Series 60 engine, when the valves at cylinder #4 are at overlap, it is indeed the correct position to set the EUI (Electronically Unit Injector) height for cylinder #6, as per Technician A. Additionally, Technician B is correct in stating that the valves at cylinder #3 can also be set in this position, following the engine's firing order and the procedure for valve and injector adjustments. This is based on the engine's design and the specific procedure for tuning up the engine, which involves setting valves and injectors in certain positions to ensure proper timing and operation.

Question 16

What is the acronym Caterpillar use to describe their EUIs?
A) ADEM
B) ACERT
C) MEUI
D) HEUI

Accepted Answer

MEUI stands for Mechanically Actuated Electronically Controlled Unit Injector, which is the acronym Caterpillar uses to describe their specific type of Electronic Unit Injectors (EUIs).

Question 17

Identify the ACERT equipped engine in the list below:
A) C15
B) C-15
C) 3406E
D) C-10

Accepted Answer

The ACERT (Advanced Combustion Emissions Reduction Technology) system was first introduced on the C15 engine in 2003.

Question 18

What type of transfer pump is used in the fuel sub-system in most EUI-fueled engines?
A) fixed clearance gear pump
B) helical gear pump
C) plunger pump
D) vane type pump

Accepted Answer

Fixed clearance gear pumps are commonly used in the fuel sub-system of EUI-fueled engines due to their reliability and ability to handle the high pressures required for fuel injection systems.

Question 19

Which of the following must happen to enable an EUI to no-fuel, and therefore shutdown, an engine?
A) EUI solenoid not be energized
B) no plunger stroke
C) camshaft does not ramp off IBC
D) camshaft ceases to rotate

Accepted Answer

The EUI (Electronic Unit Injector) solenoid must not be energized to cut off fuel supply, leading to engine shutdown.

Question 20

Which of the following determines the length of a plunger effective stroke in a single actuator EUI?
A) length of plunger downstroke
B) cam lift
C) time EUI control solenoid is energized
D) the duration of the TPS signal

Accepted Answer

The length of a plunger's effective stroke in a single actuator EUI is determined by the time the EUI control solenoid is energized, as this controls the fuel injection timing and duration.

Quiz 25: Single-Actuator Eui Systems

Which was the first computer controlled, truck diesel engine to be manufactured in North America?

What engine was the first generation of DDEC electronics (DDEC I) used on?

In what MY did single actuator EUIs cease to be used on any North American, Highway certified diesel engine?

Which of the following types of throttle position sensors (TPS) would be used on most diesel engines fueled by single actuator EUIs?

Which of the following is NOT true of the signal voltage value returned by a potentiometer type TPS if it is functioning properly?

How is EUI duty cycle usually displayed on electronic service tools (ESTs) ?

What force is used to convert charging pressures into injection pressures in EUIs?

What mechanical feature defines the limits within which EUI fuel pulse width (PW) must take place?

Which of the following terms used by DDC to describe DDEC EUI fueling has the same meaning as split shot injection?

When a typical EUI is managing pilot injection, when should the second pulse begin?

Which of the following is NOT an advantage of pilot injection?

What does the injector response time (IRT) allow DDEC electronics to do when managing EUI pulse width?

When a single-cylinder cutout test is being performed on a typical EUI-fueled engine with the objective of identifying a dead cylinder, what happens to mean (average) PW when the EUI over the dead cylinder is cut?

What electronic component houses the electronic distributor unit (EDU) in versions of DDEC fueled engines manufactured before 2007?

What is the acronym Caterpillar use to describe their EUIs?

Identify the ACERT equipped engine in the list below:

What type of transfer pump is used in the fuel sub-system in most EUI-fueled engines?

Which of the following must happen to enable an EUI to no-fuel, and therefore shutdown, an engine?

Which of the following determines the length of a plunger effective stroke in a single actuator EUI?