Automotive Technology Final (Auto 181)
An oxygen sensor is being tested using a digital storage oscilloscope (DSO). A good oxygen sensor should display how many transitions (switches) per second? a. 1 to 5 b. 5 to 10 c. 10 to 15 d. 15 to 20
A. 1 to 5
A wide-band oxygen sensor was first used on a Honda in what model year? a. 1992 b. 2000 c. 1996 d. 2006
A. 1992
Cranking vacuum should be _____ a. 2.5 inch Hg or higher b. over 25 inch Ha c. 17 to 21 inch Hq d. 6 to 16 inch Ha
A. 2.5 inch Hg or higher
Which of these tools would be used to test a MAP sensor? a. A digital voltmeter b. A Jumper wire c. A test light d. A vacuum simulator
A. A digital voltmeter
Which statement is false? a. Absolute pressure is equal to barometric pressure plus intake manifold vacuum. b. A decrease in manifold vacuum means an increase in manifold pressure. c. The MAP sensor compares manifold vacuum to a perfect vacuum. d. Barometric pressure minus the MAP sensor reading equals intake manifold vacuum.
A. Absolute pressure is equal to barometric pressure plus intake manifold vacuum
Typical TP sensor voltage at idle is about _____ a. 2.50 to 2.80 volts b. 0.5 volt or 10% of WOT TP sensor voltage c. 1.5 to 2.8 volts d. 13.5 to 15.0 volts
B. 0.5 volt or 10% of WOTP sensor voltage
Nitrous oxide injection adds ____, allowing the engine to burn more fuel. a. NOx b. Oxygen c. HC d. CO2
B. Oxygen
Boost pressure is generally measured in ____ a. inch Hq b. PSI c. inch H2O d. inch pound
B. PSI
The upper portion of a two-part intake manifold is often called the a. housing b. plenum c. lower part d. vacuum chamber
B. Plenum
A TP sensor is what type of sensor? a. Rheostat b. Potentiometer c. Voltage generating d. Piezoelectric
B. Potentiometer
When testing a MAP sensor, the technician should first check the _____ voltage. a. signal b. reference c. alternator d. back
B. Reference
Global (generic) OBD Il contains some data in what format? a. Plain English b. Roman numerals c. Hexadecimal d. All of the above
B. Roman numerals
Which wire on a TP sensor should be back-probed to check the voltage signal to the PCM? a. 5-volt reference (Vref) b. Signal c. Ground d. Meter should be connected between the 5-volt reference and the ground
B. Signal
Why is the catalytic converter placed as close to the engine as possible? a. For easier access when working on the engine b. So the heat can help the converter work most efficiently c. To allow the exhaust pipes from the catalytic converter rearward to be as long as possible d. To prevent the heat from the exhaust system moving upward toward the floor of the vehicle
B. So the heat can help the converter work most efficiently
Which of these takes place during regeneration in a diesel particulate filter (DPF)? a. The oxygen sensor is being cleaned b. Soot is being burned c. EGR system is being actively tested d. Catalytic converter is being purged
B. Soot is being burned
What part of the scope pattern shows the duration of the spark? a. Firing line b. Spark line c. Intermediate section d. Dwell section
B. Spark line
Computer speed is measured in _____ a. baud rate b. clock speed (Hz) c. voltage d. bytes
A. Baud rate
How are most turbochargers lubricated? a. By engine oil under pressure through lines from the engine b. By an internal oil reservoir c. By greased bearings d. No lubrication is needed because the incoming air cools the supercharger
A. By engine oil under pressure through lines from the engine
Which valve is used on a factory supercharger to limit boost? a. Bypass valve b. Blow-off valve c. Wastegate d. Air valve
A. Bypass valve
The chemical energy in fuel is converted to heat by the burning of the fuel at a controlled rate. This processed is called _______. A. Combustion B. Consumption C. Power D. Torque
A. Combustion
Why are the EGR gases cooled before entering the engine on some engines? a. Cool exhaust gas is more effective at controlling NOx emissions b. To help prevent the exhaust from slowing down c. To prevent damage to the intake valve d. To prevent heating the air-fuel mixture in the cylinder
A. Cool exhaust gas is more effective at controlling NOx emissions
Coil polarity is determined by the _____ a. direction of rotation of the coil windings b. turns ratio c. direction of laminations d. saturation direction
A. Direction of rotation of the coil windings
A generic (global)-type scan tool can retrieve ______ data. a. emissions-related b. brake system c. all available d. All of these
A. Emissions related
A waste-spark-type ignition system ______ a. fires two spark plugs at the same time b. fires one spark plug with reverse polarity c. fires one spark plug with straight polarity d. All of the above
A. Fires two spark plugs at the same time
The computer automatically clears a DTC if there are no additional detected faults after _____ a. forty consecutive warm-up cycles b. eighty warm-up cycles c. two consecutive trips d. four key-on/key-off cycles
A. Forty consecutive warm-up cycles
Which is a continuous monitor? a. Fuel system monitor b. EGR monitor c. Oxygen sensor monitor d. Catalyst monitor
A. Fuel system monitor
DTC P0302 is a _____ a. generic DTC b. vehicle manufacturer-specific DTC c. idle speed-related DTC d. transmission/transaxle-related DTC
A. Generic DTC
Which type of sensor uses a burn-off circuit? a. Hot wire MAF sensor b. Hot film MAF sensor c. Vane-type airflow sensor d. Both a and b
A. Hot wire MAF sensor
As the load on an engine increases, the manifold vacuum decreases and the manifold absolute pressure _______ a. increases b. decreases c. changes with barometric pressure only (altitude or weather) d. remains constant (absolute)
A. Increases
If the MAF sensor fails, the PCM uses ____ fuel delivery needs. a. MAP and throttle position to calculate b. RPM and throttle position c. Throttle position and transmission RPM d. RPM alone
A. MAP and throttle position to calculate
Selective catalytic reduction (SCR) uses urea injection to reduce ____ emissions. a. NOs b. CO2 c. H2O d. CO
A. NOs
The SAE term for the vehicle computer is _____ a. PCM b. ECM c. ECA d. Controller
A. PCM
Torque is expressed in units of ____. A. Pound-feet B. Foot-pounds C. Foot-pounds per minute D. Pound-feet per second
A. Pound-feet
A high 02S voltage could be due to a _____ a. rich exhaust b. lean exhaust c. defective spark plug wire d. Both a and c
A. Rich exhaust
The primary (low-voltage) ignition system must be working correctly before any spark occurs from a coil. Which component is not in the primary ignition circuit? a. Spark plug wiring b. Ignition module (igniter) c. Pickup coil (pulse generator) d. Ignition switch
A. Spark plug wiring
Technician A says that a crankshaft determines the stroke of an engine. Technician B says that the length of the connecting rod determines the stroke of an engine. Which technician is correct? A. Tech A only B. Tech B only C. Both Techs A and B D. Neither Techs A nor B
A. Tech A only
An oxygen sensor is being tested with a digital multimeter (DMM), using the MIN/MAX function. The readings are: minimum = 78 mV; maximum = 932 mV; average = 442 mV. Technician A says that the engine is operating correctly. Technician B says that the oxygen sensor is skewed too rich. Which technician is correct? a. Technician A only b. Technician B only c. Both Technicians A and B d. Neither Technician A nor B
A. Technician A only
Technician A says that knowing if there are any stored diagnostic trouble codes (DTCs) may be helpful when checking for related technical service bulletins (TSBs). Technician B says that only a factory scan tool should be used to retrieve DTCs. Which technician is correct? a. Technician A only b. Technician B only c. Both Technicians A and B d. Neither Technician A nor B
A. Technician A only
Two technicians are diagnosing a poorly running engine. There are no diagnostic trouble codes. When the MAF sensor is un-plugged, the engine runs better. Technician A says that this means that the MAF is supplying incorrect airflow information to the PCM. Technician B says that this indicates that the PCM is defective. Which technician is correct? a. Technician A only b. Technician B only c. Both technicians A and B d. Neither Technician A nor B
A. Technician A only
After a TP sensor has been tested using the MIN/MAX function on a DMM, a reading of zero volts is displayed, What does this reading indicate? a. The TP sensor is open at one point during the test b. The TP sensor is shorted. c. The TP sensor signal is shorted to 5-volt reference, d. Both b and c are possible.
A. The TP sensor is open at one point during the test
What is the purpose of an intercooler? a. To reduce the temperature of the air entering the engine b. To cool the turbocharger c. To cool the engine oil on a turbocharged engine d. To cool the exhaust before it enters the turbocharger
A. To reduce the temperature of the air entering the engine
The use of a variable vane turbocharger allows the elimination of the ____ a. turbocharger wastegate b. diesel oxygen sensor c. intake air cooler d. exhaust cooler
A. Turbocharger wastegate
An ignition misfire or fuel mixture problem is an example of what type of DTC? a. Type A B. Type B c. Type C d. Type D
A. Type A
What unit of electricity is used as a signal for a computer? a. Volt c. Ampere b. Ohm d. Watt
A. Volt
Which is the factory scan tool for Chrysler-brand vehicles equipped with CAN? a.WiTECH b. Tech 2 c. NGS d. Master Tech
A. WiTECH
A spark tester should be used to check for spark because ______. a. aspark tester requires at least 25,000 volts to fire b. it is connected to the CKP sensor to check its output c. it can detect a cracked spark plug d. it can detect the gap of the spark plugs
A. a spark tester requires at least 25,000 volts to fire
OBD Il has been on all passenger vehicles in the United States since _____ a. 1986 b. 1996 c. 1991 d. 2000
B. 1996
Most TP sensors have how many wires? a. 1 b. 3 c. 2 d. 4
B. 3
The typical MAF reading on a scan tool with the engine at idle speed and normal operating temperature is _____ a. 1 to 3 grams per second b. 3 to 7 grams per second c. 8 to 12 grams per second d. 14 to 24 grams per second
B. 3 to 7 grams per second
A normally aspirated automobile engine loses about _____ power per 1,000 feet of altitude. A. 1% B. 3% C. 5% D. 6%
B. 3%
A good engine should produce how much compression during a running (dynamic) compression test at idle? a. 150 to 200 PSI b. 60 to 90 PSI c. 100 to 150 PSI d. 30 to 60 PSI
B. 60 to 90 PSI
A typical MAP sensor compares the vacuum in the intake manifold to ____ a. atmospheric pressure b. a perfect vacuum c. barometric pressure d. the value of the lAT sensor
B. A perfect vacuum
A good reading for a cylinder leakage test would be ____ a. within 20% between cylinders b. all cylinders below 20% leakage c. all cylinders above 20% leakage d. all cylinders above 70% leakage and within 7% of each other
B. All cylinders below 20% leakage
Which of these smoke colors indicates excessive fuel being burned in the combustion chamber? a. Blue b. Black c. White d. Gray
B. Black
How are most superchargers lubricated? a. By engine oil under pressure through lines from the engine b. By an internal oil reservoir c. By greased bearings d. No lubrication is needed because the incoming air cools the supercharger
B. By an internal oil reservoir
Which step should be performed last when diagnosing an engine performance problem? a. Checking for any stored diagnostic trouble codes b. Checking for any technical service bulletins (TSBs) c. Performing a thorough visual inspection d. Verifying the repair
B. Checking for any technical service bulletins (TSBs)
An engine fuel temperature (EFT) sensor is used on some vehicles, since fuel temperature changes the ____ of the fuel. a. color b. density c. octane rating d. pressure
B. Density
The sensor that most determines fuel delivery when a fuel-injected engine is first started is the ______ a. O2S b. ECT sensor c. engine MAP sensor d. lAT sensor
B. ECT sensor
Horsepower is expressed in units of ____. A. Pound-feet B. Foot-pounds C. Foot-pounds per minute D. Pound-feet per second
B. Foot-pounds
How is diesel fuel ignited in a warm diesel engine? a. Glow plugs b. Heat of compression c. Spark plugs d. Distributorless ignition system
B. Heat of compression
The four basic computer functions include _____ a. writing, processing, printing, and remembering b. input, processing, storage, and output c. data gathering, processing, output, and evaluation d. sensing, calculating, actuating, and processing
B. Input, processing, storage, and output
Which is not a purpose or function of the MAP sensor? a. Measures the load on the engine b. Measures engine speed c. Calculates fuel delivery based on altitude d. Helps diagnose the EGR system
B. Measures engine speed
The smoothes out the pressure pulses in the exhaust system, allowing them to be released at an even and constant rate. a. exhaust manifold b. muffler c. intake manifold d. exhaust gas recirculation valve
B. Muffler
A reluctor is a _____ a. type of sensor used in the secondary circuit b. notched ring or pointed wheel c. type of optical sensor d. type of Hall-effect sensor
B. Notched ring or pointed wheel
When testing the ECT sensor with the connector disconnected, the technician should select what position on the DMM? a. AC volts b. Ohms c. DC volts d. Hz (hertz)
B. Ohms
How many rotations of the crankshaft are required to complete each stroke of a four-stroke cycle engine? A. One- fourth B. One-half C. One D. Two
B. One-half
A P0118 DTC is being discussed. Technician A says that the ECT sensor could be shorted internally. Technician B says that the signal wire could be open. Which technician is correct? a. Technician A only b. Technician B only c. Both Technicians A and B d. Neither Technician A nor B
B. Technician B only
Technician A says that a stuck-open wastegate can cause the engine to burn oil. Technician B says that a clogged PCV system can cause the engine to burn oil. Which technician is correct? a. Technician A only b. Technician B only c. Both Technicians A and B d. Neither Technician A nor B
B. Technician B only
Technician A says that during a power balance test, the cylinder that causes the biggest RPM drop is the weak cylinder. Technician B says that if one spark plug wire is grounded out and the engine speed does not drop, a weak or dead cylinder is indicated. Which technician is correct? a. Technician A only b. Technician B only c. Both Technicians A and B d. Neither Technician A nor B
B. Technician B only
Technician A says that glow plugs are used to help start a diesel engine and are shut off as soon as the engine starts. Technician B says that the glow plugs are turned off as soon as a flame is detected in the combustion chamber. Which technician is correct? a. Technician A only b. Technician B only c. Both Technicians A and B d. Neither Technician A nor B
B. Technician B only
Technician A says that reprogramming a PCM using the J2534 system requires a factory scan tool, while Technician B says it requires Internet access. Which technician is correct? a. Technician A only b. Technician B only c. Both Technicians A and B d. Neither Technician A nor B
B. Technician B only
Two technicians are discussing a steppod ECT circuit. Technician A says, that the sensor used for a stepped circuit is different than one used in a non-stepped circuit. Technician B says that a stepped ECT circuit uses different internal resistance inside the PCM. Which technician is correct? a. Technician A only b. Technician B only c. Both Technicians A and B d. Neither Technician A nor B
B. Technician B only
Two technicians are discussing the lAT sensor. Technician A says that the IAT sensor is more important to the operation of the engine (higher authority) than the ECT sensor. Technician B says that the PCM adds fuel if the lAT indicates that the incoming air temperature is cold. Which technician is correct? a. Technician A only b. Technician B only c. Both Technicians A and B d. Neither Technician A nor B
B. Technician B only
Two technicians are discussing the term turbo lag. Technician A says that it refers to the delay between when the exhaust leaves the cylinder and when it contacts the turbine blades of the turbocharger. Technician B says that it refers to the delay in boost pressure that occurs when the throttle is first opened. Which technician is correct? a. Technician A only b. Technician B only c. Both Technicians A and B d. Neither Technician A nor B
B. Technician B only
Which item is NOT important to know before starting the diagnosis of an engine performance problem? a. List of previous repairs b. The brand of engine oil used c. The type of gasoline used d. The temperature of the engine when the problem occurs
B. The brand of engine oil used
A pending code is set when a fault is detected on _____ a. a one-trip fault item b. the first fault of a two-trip failure c. the catalytic converter efficiency d. thermostat problem (too long to closed-loop status)
B. The first fault of a two-trip failure
Which of the following may be a symptom of injector O-ring trou- ble in a HEUI system? a. Water getting in the fuel b. The fuel filter element turning black c. Fuel pressure over 20,000 PSI d. Tailpipe exhaust temperature over 572 degrees F (300 degrees C)
B. The fuel filter element turning black
The coolant flow through the radiator is controlled by the _____. A. Size of the passages in the block B. Thermostat C. Cooling fan(s) D. Water pump
B. Thermostat
A rotating force is called ________. A. Horsepower B. Torque C. Combustion pressure D. Eccentric movement
B. Torque
What two things can a vehicle computer actually perform (output)? a. Store and process information b. Turn something on or turn something off c. Calculate and vary temperature d. Control fuel and timing only
B. Turn something on or turn something off
An SOHC V-8 engine has how many camshafts? A. One B. Two C. Three D. Four
B. Two
The preferred method to clear diagnostic trouble codes (DTCs) is to _____ a. disconnect the negative battery cable for 10 seconds b. use a scan tool c. remove the computer (PCM) power feed fuse d. cycle the ignition key on and off 40 times
B. Use a scan tool
A compression-sensing ignition is what type? a. distributor b. Waste spark c. Coil-on-plug d. Any of the above
B. Waste spark
The low oil pressure warning light usually comes on _____ a. whenever an oil change is required b. whenever oil pressure drops dangerously low (4 to 7 PSI) c. whenever the oil filter bypass valve opens d. whenever the oil filter antidrainback valve opens
B. Whenever oil pressure drops dangerously low (4 to 7 PSI
The term "volumetric efficiency" refers to the ability of an engine to ____ a. create emissions b. create heat c. pull in air d. distribute air evenly
C. Pull in air
Air filters can remove particles and dirt as small as ____ a. 5 to 10 microns b. 30 to 40 microns c. 10 to 25 microns d. 40 to 50 microns
C. 10 to 25 microns
A wide-band oxygen sensor is capable of detecting the air-fuel mixture in the exhaust from _____ (rich) to _____ (lean). a. 12:1; 15:1 b. 13:1; 16.7:1 c. 10:1;23:1 d. 8:1; 18:1
C. 10:1 ; 23:1
Engine oil pressure at 3500 RPM should be at least PSI. a. 10 b. 25 c. 35 d. 42
C. 35
A typical lAT or ECT sensor reads about 3,000 ohms when tested using a MM. This resistance represents a temperature of about _____ a. -40°F (-40°C) b. 120°F (50°C) c. 70°F (20°C) d. 284°F (140°C)
C. 70°F (20°C)
Analog signals from sensors are changed to digital signals for processing by the computer through which type of circuit? a. Digital b. Analog c. Analog-to-digital converter d. PROM
C. Analog-to-digital converter
Technician A says that MAP sensors use a 5-volt reference voltage from the PCM. Technician B says that the MAP sensor voltage is higher at idle at high altitudes compared to when the engine is operating at near sea level. Which technician is correct? a. Technician A only b. Technician B only c. Both Technicians A and B d. Neither Technician A nor B
C. Both Technicians A and B
A MAF sensor on a General Motors 3,800 V-6 is being tested for contamination. Technician A says that the sensor should show over 100 grams per second on a scan tool display when the accelerator is depressed to WOT on a running engine. Technician B says that the output frequency should exceed 7,000 Hz when the accelerator pedal is depressed to WOT on a running engine. Which technician is correct? a. Technician A only b. Technician B only c. Both Technicians A and B d. Neither Technician A nor B
C. Both technicians A and B
A P0102 DTC is being discussed. Technician A says that sensor circuit shorted-to-ground can be the cause. Technician B says that an open sensor voltage, supply circuit coud be the cause. Which technician is correct? a. Technician A only b. Technician B only c. Both Technicians A and B d. Neither Technician A nor B
C. Both technicians A and B
A P0107 DTC is being discussed. Technician A says that a defective MAP sensor could be the cause. Technician B says that a MAP sensor signal wire shorted-to-ground could be the cause. Which technician is correct? A. Technician A only B. Technician B only C. Both Technicians A and B D. Neither Technician A nor B
C. Both technicians A and B
Technician A says that a cracked exhaust manifold can affect engine operation. Technician B says that a leaking lower intake manifold gasket could cause a vacuum leak. Which technician is correct? a. Technician A only b. Technician B only c. Both Technicians A and B d. Neither Technician A nor B
C. Both technicians A and B
Technician A says that a defective spark plug wire or boot can cause an engine misfire. Technician B says that a tracked ignition coil can cause an engine misfire. Which technician is correct? a Technician A only b. Technician B only c. Both Technicians A and B d. Neither Technician A nor B
C. Both technicians A and B
Technician A says that a leaking head gasket can be tested using a chemical tester. Technician B says that a leaking head gasket can be found using an exhaust gas analyzer. Which technician is correct? a. Technician A only b. Technician B only c. Both Technicians A and B d. Neither Technician A nor B
C. Both technicians A and B
Technician A says that if the opposite DTC can be set, the problem is the component itself. Technician B says if the opposite DTC cannot be set, the problem is with the wiring or grounds. Which technician is correct? a. Technician A only b. Technician B only c. Both Technicians A and B d. Neither Technician A nor B
C. Both technicians A and B
Technician A says that some intake manifolds are plastic. Technician B says that some intake manifolds are constructed in two parts or sections: upper and lower. Which technician is correct? a. Technician A only b. Technician B only c. Both Technicians A and B d. Neither Technician A nor B
C. Both technicians A and B
Technician A says the first step in the diagnostic process is to verify the problem (concern). Technician B says the second step is to perform a thorough visual inspection. Which technician is correct? A. Technician A only B. Technician B only C. Both technicians A and B D. Neither Technician A nor B
C. Both technicians A and B
Two technicians are discussing a no-start (no-spark) condition. Technician A says that an open CKP sensor could be the cause. Technician B says that a defective ignition control module (ICM) could be the cause. Which technician is correct? A. Technician A only B. Technician B only C. Both technicians A and B D. Neither technicians A nor B
C. Both technicians A and B
Two technicians are discussing oil leaks. Technician A says that an oil leak can be found using a fluorescent dye in the oil with a black light to check for leaks. Technician B says clean the engine with a degreaser when trying to locate oil leaks. Which technician is correct? a. Technician A only b. Technician B only c. Both Technicians A and B d. Neither Technician A nor B
C. Both technicians A and B
The "brain" of the computer is the _____ a. PROM b. RAM c. CPU d. AD converter
C. CPU
When testing an ECT sensor on a vehicle, a digital multimeter can be used and the signal wires back probed. What setting should the technician use to test the sensor? a. AC volts b. Ohms c. DC volts d. Hz (hertz)
C. DC volts
As the altitude of the vehicle increases, BARO voltage _____ a. increases b. does not change c. decreases d. Either b or c depending on the vehicle
C. Decreases
If the transmission fluid temperature (FT) sensor indicates cold automatic transmission fluid temperature, what does the PCM do to the shifts? a. Normal shifts and normal operation of the torque converter clutch b. Disable torque converter clutch; normal shift points c. Delayed shift points and torque converter clutch disabled d. Normal shifts but overdrive is disabled
C. Delayed shift points and torque converter clutch disabled
HEl and EIS are examples of _____ a. Waste-spark systems b. Coil-on-plug ignition systems c. Distributor ignition systems d. Pickup coil types
C. Distributor ignition systems
Air that enters the engine without passing through the airflow sensor is called ____ a. bypass air b. false air c. dirty air d. measured air
C. False air
Theoxygen sensorsignal is used by the PCM to _____ the air-fuel mixture. a. dampen b. add air to c. fine-tune d. add fuel to
C. Fine-tune
When the engine is at idle speed, manifold vacuum is ______ a. low (1 to 4 in. Hg) b. fluctuating from 8 to 10 in. Hg c. high (17 to 21 in. Hg) d. zero
C. High (17 to 21 in. Hg)
Which diesel system supplies high-pressure diesel fuel to all of the injectors all of the time? a. Distributor b. Inline c. High-pressure common rail d. Rotary
C. High-pressure common rail
Because of _____ an ignition coil cannot be fully charged (reach magnetic saturation) until after a delay of about 10 milliseconds a. voltage drop across the ignition switch and related wiring b. resistance in the coil windings c. inductive reactance d. saturation
C. Inductive reactance
Typical primary coil resistance specifications usually range from _____ ohms. a. 100 to 450 b. 500 to 1,500 c. Less than 1 to 3 d. 6,000 to 30.000
C. Less than 1 to 3
By looking at the way diagnostic trouble codes are formatted, which DC could indicate that the gas cap is loose or defective? a. P0221 b. P0442 c. P1301 d. P1603
C. P0442
What service operation is most important on engines equipped with a turbocharger? a. Replacing the air filter regularly b. Replacing the fuel filter regularly c. Regular oil changes d. Regular exhaust system maintenance
C. Regular oil changes
The voltage output of a zirconia oxygen sensor when the exhaust stream is lean (excess oxygen) is a. relatively high (close to 1 volt) b. about in the middle of the voltage range c. relatively low (close to 0 volt) d. Either a or b, depending on atmospheric pressure
C. Relatively low (close to 0 volt)
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(n) _____ type of system. a. air vane-controlled b. mass airflow c. speed density d. hot wire
C. Speed density
What color exhaust smoke occurs most often during cold engine starts because the smoke is usually condensed fuel droplets? a. Grey b. Blue c. White d. Black
C. White
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? a. 284°F (140°C) b. 120°F (50°C) c. 230°F (110°C) d. -40°F (-40°C)
D. -40°F (-40°C)
Typical secondary coil resistance specifications usually range from _____ ohms. a. 100 to 450 b. 500 to 1,500 c. 1 to 3 d. 6,000 to 30,000
D. 6,000 to 30,000
One cylinder of an automobile four-stroke cycle engine completes a cycle every ____. A. 90 degrees B. 180 degrees C. 360 degrees D. 720 degrees
D. 720 degrees
A P0122 TC is retrieved using a scan tool. This DITC means _____ a. the TP sensor voltage is low b. the TP sensor could be shorted-to-ground C. the TP sensor signal circuit could be shorted-to-ground d. All of the above.
D. All of the above
An ion-sensing ignition system allows the ignition system itself to be able to ______ a. detect misfire b. detect spark knock c. detect rich or lean air-fuel mixture d. All of the above
D. All of the above
The comprehensive component monitor checks computer-controlled devices for _____ a. opens b. rationality c. shorts-to-ground d. All of the above
D. All of the above
The ignition module has direct control over the firing of the coil(s) of an El system. Which component(s) triggers (controls) the module? a. Pickup coil b. Computer c. Crankshaft sensor d. All of the above
D. All of the above
What should be inspected as part of a visual inspection of the Ignition system? a. Spark plug wires for proper routing b. Spark plug gap c. Coil polarity d. All of the above
D. All of the above
Which item is a computer input sensor? a. RPM b. Throttle position c. Engine coolant temperature d. All of the above
D. All of the above
Which item is a computer output device? a. Fuel injector b. Transmission shift solenoid c. Evaporative emission control solenoid d. All of the above
D. All of the above
Poor engine performance could be the result of a _____ a. defective coil b. distributor ignition with the CMP and CKP not correctly indexed c. a high-voltage spark leak d. Any of the above
D. Any of the above
Which method can be used to reprogram a PCM? a. Remote b. Off-board c. Direct d. Any of the above
D. Any of the above
Which of the following is/are terms for a variable intake manifold? a. Variable intake system (VIS) b. Variable volume induction WI) C. Dual-stage intake (DSI) d. Any of the above
D. Any of the above
A low 02S voltage could be due to a a. rich exhaust b. defective spark plug wire c. lean exhaust d. Both b and c
D. Both b and c
After a TP sensor has been tested using the MIN/MAX function on a DMM, a reading of 5 volts is displayed. What does this reading indicate? a. The TP sensor is open at one point during the test b. The TP sensor is shorted. c. The TP sensor signal is shorted to 5-volt reference. d. Both b and c are possible.
D. Both b and c are possible
All OBD-Il vehicles use what type of read-only memory? a. ROM b. EPROM c. PROM d. EEPROM
D. EEPROM
Which sensor does the TP sensor back up if the PCM determines that a failure has occurred? a. Oxygen sensor b. MAF sensor c. MAP tsensor d. Either b or c
D. Either b or c
The MAF sensor is used mostly by the PCM to determine the amount of ____ to deliver to the engine. a. vacuum correction b. spark advance c. idle air d. fuel
D. Fuel
What part should be removed to test cylinder compression on a diesel engine? a. Injector b. Intake valve rocker arm and stud c. Glow plug d. Glow plug or injector
D. Glow plug or injector
A technician attaches one lead of a digital voltmeter to the ground terminal of the TP sensor and the other meter lead to the negative terminal of the battery. The ignition is switched to on, engine off and the meter displays 37.3 mV. Technician A says that this is the signal voltage and is a little low. Technician B says that the TP sensor ground circuit has excessive resistance. Which technician is correct? a. Technician A only b. Technician B only c. Both Technicians A and B d. Neither Technician A nor B
D. Neither Technician A nor B
Two technicians are discussing Karman Vortex sensors. Technician A says that they contain a burn-off circuit to keep them clean. Technician B says that they contain a movable vane. Which technician is correct? a. Technician A only b. Technician B only c. Both Technicians A and B d. Neither Technician A nor B
D. Neither technician A nor B
What type of sensor is used to measure the position of the throttle? a. Negative temperature coefficient (NTC) thermistor. b. Positive temperature coefficient (PTC) thermistor. c. Engine speed (RPM). d. Potentiometer.
D. Potentiometer
As engine speed increases, the timing of the spark in the cylinder must be _____ a. advanced b. maintained the same c. set at 10 degrees BTDC d. retarded slightly
D. Retarded slightly
The air filter restriction indicator uses what to detect when it signals to replace the filter? a. Number of hours of engine operation b. Number of miles of vehicle travel c. The amount of light that can pass through the filter d. The amount of restriction measured in inches of water
D. The amount of restriction measured in inches of water
Why do many port fuel-injected engines use long intake manifold runners? a. To reduce exhaust emissions b. To heat the incoming air c. To increase high-RPM power d. To increase low-RPM torque
D. To increase low-RPM torque
Which of the following is the least likely to cause an engine noise? a. Carbon on the pistons b. Cracked exhaust manifold c. Loose accessory drive belt d. Vacuum leak
D. Vacuum leak
What fuel system component is used in a vehicle equipped with a diesel engine that is seldom used on the same vehicle when it is equipped with a gasoline engine? a. Fuel filter b. Fuel supply line c. Fuel return line d. Water-fuel separator
D. Water-fuel separator
Which wide-band oxygen sensor incorporates a pump cell? a. The single cell type b. The dual cell type c. Both A and B d. Neither A nor B
The dual cell type
A freeze-frame is generated on an OBD-Il vehicle _____ a. When a type C or D diagnostic trouble code is set b. When a type A or B diagnostic trouble code is set c. Every other trip d. When the PCM detects a problem with the O2S
When a type A or B diagnostic trouble code is set
