Advanced Automotive System 2 Final Review Questions
What type of sensor measures speed?
Frequency generator
All of the following statements are correct EXCEPT ____________.
Fuel injectors on a gang fire system are wired in series
The electric fuel pump is usually mounted in which of these locations?
Fuel tank
Which is NOT a purpose or function of the MAP sensor?
Helps diagnose the EGR system
When compared to a port fuel injected engine, a DGI engine will have a ___________ compression ratio.
Higher
A fuel injection system that does not use a sensor to measure the amount (or mass) of air entering the engine is usually called a (an) type of system.
Hot wire
The sensor that measures the temperature of the air being drawn into the engine is called which of the these?
IAT
Where is sensor 1, bank 1 located on a V-type engine?
In the exhaust manifold and on the same bank where number 1 cylinder is located
As the load on an engine increases, the manifold vacuum decreases and the manifold absolute pressure ___________.
Increase
What happens to the voltage measured at the ECT sensor when the thermostat opens?
Increases slightly
The primary purpose of the fuel trim is to keep the air-fuel mixture as close to _________ as possible
Lambda and 14.7:1
Which of these service procedures is being done in the below illustration?
Measuring fuel pressure
The use of an electronic throttle control (ETC) system allows the elimination of all of theses EXCEPT ______________.
Mechanical throttle cable (most systems)
A clogged EGR could cause excessive ___________ exhaust emissions.
NOx
In the below illustration what type of circuit is depicted?
Negative temperature coefficient (NTC) thermistor
This DVOM reading indicates a temperture of _________ for a GM ECT sensor.
Neither A nor B
The sensor that must be warmed and functioning before the engine management computer will go to closed loop is the __________.
O2S
When testing an ECT sensor with the connector disconnected, the technician should select what position on the DMM (digital multimeter)?
Ohms
A TP sensor is what type of sensor?
Potentiometer
Which of the following is a three-wire variable sensor?
Potentiometer
When removing a high pressure line on a GDI engine, what should the technician do?
Replace the line with a new part
What should be done if the fuel pressure regulator will NOT hold vacuum?
Replacement
The throttle body may be cleaned (if recommended by the vehicle manufacturer) if what condition are occurring?
Rough idle, Coast-down stall, lower-than-normal idle speed, all of the above
An EGR valve that is partially stuck open would most likely cause what condition?
Rough idle/stalling
Fuel lines are constructed from ________.
Seamless steel tubing and Nylon plastic
Which wire on a TP sensor should be back probed to check the voltage signal to the PCM?
Signal wire
Which fuel-injection system uses the MAP sensor as the primary sensor to determine the base pulse width?
Speed density
This illustration, shows a ______________ type of combustion chamber.
Spray-guided
A corroded connector at the ECT could cause __________.
Stored DTC, Air-fuel mixture too rich, Poor fuel economy, All of these
Which mode of operation results in a richer air-fuel mixture near the spark plug?
Stratified
All of the following are approved methods for diagnosing a ECT sensor EXCEPT ___________.
Substituting a variable resistor
Which sensor has the greatest influence on injector pulse width besides the MAF sensor?
TP
A DTC P0117 DTC is being discussed. Tech A says that the ECT sensor could be internally shorted to ground. Tech B says that the signal wire could be open. Which tech is correct?
Tech A
Some states have a testing program that uses I/M 240 testing procedures. The number 240 refers to ___________.
The length of the loaded mode test, 240 seconds
What type of sensor measures temperature?
Thermistor
Why is a vacuum line attached to a fuel-pressure regulator on many port fuel-injected engines?
To create an equal pressure drop across the injectors
When the brake pedal is pressed the brake switch causes the TCM to release the _____________.
Torque converter clutch
The input speed sensor is also called a _________________.
Turbine speed sensor (TSS)
An IAT is being tested. After the vehicle has been allowed to cool for several hours, a scan tool is used to observe the IAT sensor reading. When compared to the engine coolant temperature (ECT), the two temperatures should be within how many degrees F of each other:
5
The output of a MAP sensor is reading 1.0 volt. What is the approximate engine vacuum in inches of Mercury (Hg)?
17-21
Most fuel filters are designed to remove particles larger than ________.
20 microns
At what temperature dose oxygen combine with the nitrogen in the air to form NOx?
2500°F (1370°C)
The MAP sensor is used to check the operation of the _________ on OBD II vehicles.
EGR system
With the vehicle in closed loop,, the following post converter HO2S scope pattern activity is seen. What dose this indicate?
A bad converter
With the vehicle in closed loop,, the following post converter HO2S scope pattern activity is seen. What dose this indicate?
A good converter
A low O2S voltage could be due to _____________.
A lean exhaust and a defective spark plug wire
A typical MAP sensor compares the vacuum in the intake manifold to ______.
A perfect vacuum
A high O2S voltage could be due to ___________.
A rich exhaust
The SIDI high pressure fuel pump uses a single-barrel piston plunger that is driven by __________.
A three-lobed cam
What electronic control module is used to control the shifting of an electronically controlled automatic transmission/ transaxle?
Any of the above, depending on application
Which component of this GDI high pressure pump is the pressure regulator?
A
When checking the ECT sensor with a scan tool, about what temperature should be displayed if the connector is removed from the sensor with the key on, engine off?
-40°F (-40°C)
With the TP sensor in the position shown, what voltage would be expected at the signal wire (C)?
0.5 volts
A conventional oxygen sensor heater uses about __________ amps.
0.8 to 2.0
In this diagram, which terminals are used for the TP sensors?
1,2,4,6
A wide band oxygen sensor is capable of detecting the air-fuel mixture in the exhaust from _____ (rich) to_____ (lean)
10:1 to 23:1
The fuel pump inside the fuel tank on a vehicle equipped with gasoline direct injection produces about what pressure?
50 to 60 PSI
The fuel injectors used on a gasoline direct injection system are pulsed on using what voltage?
50 to 90 V
GDI fuel injectors operate under a pressure of about ________.
500 to 2,900 PSI
A conventional oxygen sensor heater keeps the sensor at about ___________ degrees F.
600
The first fuel filter in the sock inside the fuel tank normally filters particles larger than _______________.
70 to 100 microns
A typical IAT or ECT sensor reads about 3000 ohms when tested using a DMM. This resistance represents a temperature of about _________.
70°F (20°C)
Identify the throttle position sensor assembly in this diagram.
A
Which component in this photograph is the drive (motor) gear?
A
How long dose the electric fuel pump run if the ignition is turned on but the engine is not started?
About 2 seconds
Fuel injectors can be tested using _____________.
All of the above
All these are returnless fuel systems EXCEPT ______________.
All of these are types of returnless systems
All theses are causes of catalytic converter failure EXCEPT ___________.
All of theses are causes of converter failure
The component shown (shaped) has a crack or split in it. What would this cause?
Allow false air into the engine
Which of these vehicle types would be classified as a ZEV vehicle?
An electric vehicle and a fuel cell powered vehicle
The wiring to the IAT sensor has high resistance (cut wire). What could this cause?
Black exhaust smoke and poor fuel economy
A P0401 is being discussed. Tech A says that a stuck-closed EGR valve could be the cause. Tech B says that clogged EGR ports could be the cause. Which tech is correct?
Both techs
Tech A says that MAP sensors uses a 5-volt reference voltage from the PCM. Tech B says that the MAP sensor voltage will be higher at idle at high altitudes compared to when the engine is operating at near sea level. When tech is correct?
Both techs
Tech A says that the ECT and IAT sensor can be tested visually, as well as by using a digital multimeter or a scan tool. Tech B says that the ECT sensor is a high-authority sensor at engine startup and is used for open-loop control, as well as idle speed. Which tech is correct
Both techs
Tech A says that the fuel pump relay is usually controlled by the PCM. Tech B says that a TBI injector squirts fuel above the throttle plate. Which tech is correct?
Both techs
Tech A says that the purpose of the intake air temperature (IAT) sensor is to provide the engine computer (PCM) with the temperature of the air entering the engine. Tech B says the the IAT sensor information is used for fuel control (adding or subtracting fuel) and sparking timing, depending on the temperature of incoming air. Which tech is correct
Both techs
Tech A says that vehicles with electronic relentless fuel systems use pulse width modulation to power the fuel pump and maintain fuel pressure. Tech B says that the electronic returnless fuel system uses a power transistor to control the fuel pump. Which tech is correct?
Both techs
The fuel pressure drops rapidly when the engine is turned off. Tech A says that one or more injectors could be leaking. Tech B says that a defective check valve in the fuel pump could be the cause. Which tech is correct?
Both techs
A sequential fuel injection system uses a ____________ to time the fuel injection pulses.
CMP sensor
A lack of power from an engine equipped with gasoline direct injection could be due to _____________.
Carbon on the intake valves and carbon on the injectors
Which term describes the PCM using oxygen sensor feedback to control fuel delivery?
Closed loop mode
When testing an ECT sensor on a vehicle, a digital multimeter can be used and the signal wire back probed. What setting should the technician use to test the sensor?
DC volts
If the transmission fluid temperature (TFT) sensor indicates cold automatic transmission fluid temperature, what would the PCM do the shifts?
Delayed shift points and torque converter clutch disabled
Where is the fuel injectors in an engine equipped with gasoline direct injection?
Directly in the combustion chamber
The sensor that most determines fuel delivery when a fuel injected engine is first started is the __________.
ECT sensor
Which of the following components provides the engine control computer with engine coolant temperature information?
ECT sensor
Which of these tools is best to check whether the PCM is pulsing an injector?
Noid light
Tech A says that an oxygen sensor produces a voltage output signal based on the oxygen content of the exhaust stream. Tech B says that of the exhaust has little oxygen the voltage of the oxygen sensor will be close to 0 volts. Which tech is correct?
Tech A
Tech A says that other temperature sensors that operate like the ECT include the transmission fluid temperature (TFT), and cylinder head temperature sensor. Tech B says that all temperature sensors increase in resistance as the temperature decreases. Which tech is correct?
Tech A
A DTC P0113 DTC is being discussed. Tech A says that the IAT sensor could be internally (electrically) shorted to ground. Tech B says that the PCM could be defective. Which tech is correct?
Tech B
A P0118 DTC is being discussed. Tech A says that the ECT sensor could be shorted internally. Tech B says the signal wire could be open. Which tech is correct?
Tech B
Tech A says that all temperature sensors are PTC devices that decrease in resistance as the temperature increases. Tech B says that some vehicle manufacturers use a stepped ECT circuit inside the PCM to broaden the accuracy of the sensor. Which tech is correct?
Tech B
Tech A says that carbon should be cleaned out after installing a new EGR valve. Tech B cleans the EGR exhaust passages by using a stranded metal cable. Which tech is correct?
Tech B
Two techs are discussing the IAT sensor. Tech A says that the IAT sensor is more important to the operation of the engine (higher authority) than the ECT sensor. Tech B says that the PCM will add fuel if the IAT indicates that the incoming air temperature is cold. Which tech is correct?
Tech B
The high-pressure fuel pumps used in gasoline direct injection(GDI) systems are powered by ______________.
The camshaft
A throttle body relearn procedure uses ________ to relearn proper idle speed?
The ignition switch
When dose the PCM perform a self test of the ETC system?
When the ignition switch is first rotated to the on position, before the engine starts
Two techs are discussing a stepped ECT circuit. Tech A says that the sensor used for a stepped circuit is different than one used in a non-stepped circuit. Tech B says that a stepped ECT circuit uses different internal resistance inside the PCM. Which tech is correct?
`Tech B
