Deck 4: Common Operating Principles for Computerized Engine Control Systems

Question 1

In a GDI system the fuel injectors spray fuel directly into the combustion chamber and require higher fuel pressures under heavy load, typically as high as:

A) 150 PSI
B) 625 PSI
C) 2,140 PSI
D) 10,500 PSI

Answer 1

C

Question 2

Technician A says one advantage of a variable valve timing system is that it allows a higher-compression engine to burn a lower octane fuel while still being able to control the potential for detonation. Technician B says that most VVT systems use engine oil pressure to control them hydraulically. Who is correct?

A) Technician A only
B) Technician B only
C) Both technicians
D) Neither technician

Answer 2

C

Question 3

All of the following are used to combat the potential for vapor lock to occur EXCEPT :

A) The addition of a fuel return line
B) The deletion of the fuel return line
C) The relocation of the fuel pump back to within the fuel tank
D) The use of higher pressures within the fuel management system

Answer 3

B

Question 4

Reid Vapor Pressure (RVP) is a unit of measurement used to measure a fuel's:

A) Alcohol content
B) Ability to atomize
C) Octane
D) Volatility

Question 5

Technician A says that if a fuel supply line ruptures during an accident resulting in fuel pressure loss and engine stall, the PCM will shut down the fuel pump. Technician B says that the fuel pump is controlled by the ignition switch only and should always run whenever the ignition switch is in the "run" position. Who is correct?

A) Technician A only
B) Technician B only
C) Both technicians
D) Neither technician

Question 6

What level of tach reference information is required for the PCM to properly control a COP ignition system?

A) Level one information indicating that "a pair of cylinders`pistons is approaching TDC"
B) Level two information indicating "which pair of cylinders`pistons is approaching TDC"
C) Level three information indicating "which cylinder of the piston pair approaching TDC is on the compression stroke"
D) None of this information is required for the PCM to control a COP ignition system

Question 7

With the engine running, how is the PCM programmed to pulse the fuel injectors in a sequential fuel injection (SFI/SMPI) system?

A) Pulse all injectors simultaneously once each crankshaft revolution
B) Pulse one half of the injectors simultaneously on each crankshaft revolution
C) Pulse the injectors in pairs
D) Pulse the injectors individually in the engine's firing order

Question 8

What is the primary purpose for replacing 14-volt systems with 42-volt systems?

A) To eliminate the charging system
B) To make the vehicle's electrical systems safer to work on
C) To increase the KV that the ignition coil(s) can provide
D) To provide more total wattage than a 14-volt system can provide

Question 9

The emission system that is designed to route ambient air into the exhaust manifold during cold engine warm up only is known as:

A) EGR
B) AIR
C) EVAP
D) PCV

Question 10

What level of tach reference information is required in order for the PCM to properly control a "Waste Spark" ignition system?

A) Level one information indicating that "a pair of cylinders`pistons is approaching TDC"
B) Level two information indicating "which pair of cylinders`pistons is approaching TDC"
C) Level three information indicating "which cylinder of the piston pair approaching TDC is on the compression stroke"
D) None of this information is required in order for the PCM to control a "Waste Spark" system

Question 11

With modern terminology, the acronym "DI" refers to which type of ignition system?

A) A distributor ignition system using only one ignition coil
B) A "Waste Spark" distributorless ignition system using one ignition coil for each pair of cylinders
C) A "Coil-On-Plug" distributorless ignition system using one ignition coil for each cylinder
D) Both B and C

Question 12

Technician A says that on fuel injection systems, the fuel pump relay carries the high amperage current for the fuel pump. Technician B says that on fuel injection systems with a return line, the fuel pressure regulator is located after the fuel pump and before the fuel injectors. Who is correct?

A) Technician A only
B) Technician B only
C) Both technicians
D) Neither technician

Question 13

In an electronic return-less SMPI system, the PCM controls all of the following EXCEPT:

A) Intake manifold pressure
B) Fuel pump speed
C) Fuel rail pressure
D) Fuel pressure differential across the fuel injectors

Question 14

What level of tach reference information is required in order for the PCM to properly control a distributor ignition system?

A) Level one information indicating that "a pair" of cylinders' pistons are approaching TDC
B) Level two information indicating "which pair" of cylinders' pistons are approaching TDC
C) Level three information indicating which cylinder of the piston pair approaching TDC is on the compression stroke
D) None of this information is required in order for the PCM to control a distributor ignition system

Question 15

During closed-loop operation of a fuel injection system, the PCM is programmed to perform all of the following functions EXCEPT :

A) controlling how much fuel is introduced into the intake manifold
B) fine-tuning the air-fuel ratio to minimize toxic emissions while maximizing fuel economy
C) retaining good driveability under cruise and light-to-moderate acceleration
D) maximizing driveability during cold starts and hard accelerations

Question 16

What level of tach reference information is required in order for the PCM to properly control an SFI fuel management system?

A) Level one information indicating that "a pair of cylinders`pistons is approaching TDC"
B) Level two information indicating "which pair of cylinders`pistons is approaching TDC"
C) Level three information indicating "which cylinder of the piston pair approaching TDC is on the compression stroke"
D) None of this information is required in order for the PCM to control a SFI fuel management system.

Question 17

In order to ease cold weather starting, gasoline refiners produce gasoline in the winter months that has a:

A) Lower volatility
B) Higher volatility
C) Lower octane
D) Higher octane

Question 18

The emission control system that is designed to recirculate blow by gasses from the crankcase to the intake manifold is known as:

A) PCV
B) EGR
C) EVAP
D) AIR

Question 19

When battery voltage drops below a specified value, the PCM:

A) increases ignition dwell to compensate for a weakened ignition spark
B) enters open-loop operation
C) enriches the air-fuel mixture
D) Both A and C

Question 20

A homogeneous charge compression ignition (HCCI) engine:

A) uses heat to auto-ignite the air-fuel charge
B) produces far less noise and vibration than a gasoline engine
C) creates more emissions than a gasoline engine
D) works most efficiently with a rich air-fuel ratio