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Bartleby Sitemap - Textbook Solutions

All Textbook Solutions for Automotive Technology: A Systems Approach (MindTap Course List)

Describe the typical procedure for adjusting a TP sensor.Why does the rotor for a CKP have one or more missing teeth?A system may fail the catalyst monitor test for all of these reasons, except. defective upstream or downstream oxygen sensor circuits a leaking exhaust fuel contaminants ignition system faults A defective LAT sensor or circuit may cause the fol lowing problems, except. hard engine starting rich or lean air-fuel ratio improper converter clutch lockup reduced fuel economy Which of the following is the least likely cause of a no-start condition? Faulty CKP sensor Faulty KS Fuel or ignition system faults Faulty PCM wiring Technician A says that an oxygen sensor can be a voltage-producing sensor. Technician B says that an oxygen sensor is a thermistor sensor. Who is correct? Technician A Both A and B Technician B Neither A nor B 2ASRQ While discussing ECT sensor diagnosis: Technician A says that a defective ECT sensor may cause hard cold engine starting. Technician B says that a defective ECT sensor may cause improper operation of emission control devices. Who is correct? Technician A Technician B Both A and B Neither A nor B While discussing Hall-effect vehicle speed sensor tests: Technician A says to use an ohmmeter to test the resistance of the coil. Technician B says that the voltage generated by the sensor can be measured by connecting a voltmeter across the sensors terminals. Who is correct? Technician A Technician B Both A and B Neither A nor B While discussing TP sensor diagnosis: Technician A says that a four-wire TP sensor contains an idle switch. Technician B says that in some applications, the TP sensor mounting bolts may be loosened and the TP sensor housing rotated to adjust the voltage signal with the throttle in the idle position. Who is correct? Technician A Technician B Both A and B Neither A nor B While diagnosing the cause of a hard starting condition: Technician A checks the ECT sensor. Technician B checks the MAP sensor. Who is correct? Technician A Technician B Both A and B Neither A nor B While discussing testing OBD II system components: Technician A says that a testlight can be used to test O2S output. Technician B says that a digital voltmeter can be used to test the O2S. Who is correct? Technician A Technician B Both A and B Neither A nor B When testing a frequency varying MAF: Technician A says that the frequency should increase with an increase in engine speed. Technician B says that when observed on a lab scope, the signal from the sensor should be a square wave. Who is correct? Technician A Technician B Both A and B Neither A nor B Technician A says that a faulty MAF sensor can cause the engine to run lean. Technician B says that a faulty MAP sensor can cause the engine to not start. Who is correct? Technician A Technician B Both A and B Neither A nor B While discussing the MIL on OBD 11 systems: Technician A says that the MIL will flash if the PCM detects a fault in a sensor or circuit. Technician B says that as soon as the PCM has detected a fault, it will turn on the MIL. Who is correct? Technician A Technician B Both A and B Neither A nor B Explain how voltage is induced in a permanent magnet pickup coil as the reluctor approaches alignment with the pickup coil.Explain why dwell time is important to ignition system operation.3RQ Explain how the plugs fire in a two-plug-per-coil DIS system.Explain the components and operation of a Hall-effect sensor.6RQ True or False? A spark plug with two ground electrodes will provide two separate sparks when fired.Why is high voltage needed to establish a spark across the gap of a spark plug?9RQ Which of the following is a function of all ignition systems? a. To generate sufficient voltage to force a spark across the spark plug gap b. To time the arrival of the spark to coincide with the movement of the engines pistons c. To vary the spark arrival time based on varying operating conditions d. All of the above Reach, heat range, and air gap are all characteristics that affect the performance of which ignition system component? a. Ignition coils b. Ignition cables c. Spark plugs d. Ignition modules True or False? The spark plug wire is eliminated in all coil-per-cylinder ignition systems to reduce maintenance and the chances of EMI and RFI.Modern ignition cables contain fiber cores that act as a in the secondary circuit to cut down on radio and television interference and reduce spark plug wear.The magnetic field surrounding the coil in a magnetic pulse generator moves when the. a. Reluctor tooth approaches the coil b. Reluctor tooth begins to move away from the pickup coil pole c. Reluctor is aligned with the pickup coil pole d. Both a and b Which of the following electronic switching devices has a reluctor with wide shutters rather than teeth? a. Magnetic pulse generator b. Optical sensor c. Hall-effect sensor d. All of the above Technician A says that a magneto resistive sensor is equipped with a permanent magnet. Technician B says that a Hall-effect switch is equipped with a permanent magnet. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A nor B While discussing ignition systems: Technician A says that an ignition system must supply high-voltage surges to the spark plugs. Technician B says that the system must maintain the spark long enough to burn all of the air-fuel mixture in the cylinder. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A nor B While discussing ignition timing requirements: Technician A says that more advanced timing is desired when the engine is under a heavy load. Technician B says that more advanced timing is desired when the engine is running at high engine speeds. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A nor B While discussing secondary voltage: Technician A says that the normal required secondary voltage is higher at idle speed than at wide-open throttle conditions. Technician B says that the maximum available secondary voltage must always exceed the normally required secondary voltage. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A nor B 5ASRQ In El systems using one ignition coil for every two cylinders: Technician A says that two plugs fire at the same time with the same voltage used by each spark plug. Technician B says that one plug fires in the normal direction (center to side electrode) and the other in reversed polarity (side to center). Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A nor B While discussing EI systems: Technician A says that all systems rely on CKP and CMP signals to synchronize the ignition system with piston movement. Technician B says that CKP and CMP signals are used to synchronize the operation of the ignition and fuel injection systems with piston position. Who is correct? a. Technician A b. Both A and B c. Technician B d. Neither A nor B While discussing El systems: Technician A says that when the engine is being cranked, the PCM relies only on the signals from the ECT to determine initial ignition timing. Technician B says that when an engine is initially started and is running at a predetermined speed, the PCM looks at several inputs, including engine speed, load, throttle position, and engine coolant temperature, and makes adjustments accordingly. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A nor B Technician A says the switching device controls the flow of current through the coil primary winding. Technician B says that when the switching device stops supplying current to the coil primary winding, it is time to fire the spark plug. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A nor B While discussing spark plugs: Technician A says that too narrow of a spark plug gap can cause a rough idle and premature wear of the electrodes. Technician B says that a spark plug with the wrong reach can cause preignition. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A nor B Name the three types of stress testing used to test for intermittent ignition component problems and list the procedures for conducting each type of test.2RQ Name the three types of trace pattern display modes used on an oscilloscope and give examples of when each mode is most useful.4RQ List at least two methods of checking the operation of Hall-effect sensors.What happens if one of the ground electrodes of a spark plug with two or more electrodes is closer to the center electrode than the other?True or False? The first test when checking a no-start condition is to check all input signals.Richer air-fuel mixtures. a. decrease the electrical resistance inside the cylinder and decrease the required firing voltage b. increase the electrical resistance inside the cylinder and increase the required firing voltage c. increase the electrical resistance inside the cylinder and decrease the required firing voltage d. have no measurable effect on cylinder resistance 9RQ What does a slope in the spark line represent?True or False? On some engines, if the gap between the crankshaft sensor and its trigger wheel is outside specifications, the sensor should be replaced.What is the typical procedure for checking the resistance of the primary winding in an ignition coil?While checking a pickup coil with an ohmmeter, a lower-than-normal reading indicates that the pickup unit is a. shorted b. open c. has high resistance d. none of the above A CKP sensor can be checked with all of the following except a(n). a. logic probe b. voltmeter c. ammeter d. lab scope Which of the following will cause one or more, but not all, firing lines to be higher than normal? a. High resistance in the spark plug wire b. Faulty fuel injector c. Defective spark plug d. All of the above 1ASRQ 2ASRQ 3ASRQ Technician A says that EMI can affect sensor signals. Technician B says that EMI can cause intermittent driveability problems. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A nor B While discussing waste spark EI systems: Technician A says that a spark plug with too wide of a gap can affect the firing of its companion spark plug. Technician B says that improper spark plug torque can cause an engine misfire. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A nor B While discussing how to test a Hall-effect crankshaft position sensor: Technician A says that a logic probe can be used. Technician B says that a DMM can be used. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A nor B While discussing the possible causes for a no-start condition on an EI-equipped engine: Technician A says that a shorted crankshaft sensor may prevent the engine from starting. Technician B says that a faulty ignition coil may stop the engine from starting. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A nor B 8ASRQ While discussing EI service and diagnosis: Technician A says that the crankshaft sensor may be rotated to adjust the basic ignition timing. Technician B says that the crankshaft sensor may be moved to adjust the clearance between the sensor and the rotating blades on some EI systems. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A nor B While discussing engine misfire diagnosis: Technician A says that a defective EI coil may cause cylinder misfiring. Technician B says that a shorted CKP could cause a misfire. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A nor B Pump gasoline may contain a small amount of alcohol. Name three problems that can occur if there is an excessive amount of alcohol in gasoline.True or False? The diesel fuels antiknock quality is measured by the cetane rating.What percentage of ethanol does E85 contain?List five advantages the use of piezoelectric injectors has over solenoid-based injectors.What does the Reid vapor pressure (RVP) test measure?List three alternative fuels for an internal combustion engine and briefly explain where they come from.Why is the sulfur content in gasoline limited?8RQ What is particulate matter and when is it produced?What are oxygenates and why are they added to refined gasoline?How does SCR lower the content in a diesels exhaust?True or False? Piezoelectric materials can emit a small amount of voltage when they are struck, squeezed, or exposed to vibration.Name three driveability factors that are affected by the volatility of gasoline.Which of the following statements about hydrogen is not true? a. Hydrogen displaces air, so any release in an enclosed space could cause asphyxiation. b. Hydrogen must be stored as a compressed gas. c. Hydrogen is nontoxic. d. Hydrogen is highly flammable and there is risk for an explosion.Which of the following chemicals is commonly added to gasoline to increase its octane rating? a. Isooctane b. Heptane c. Sulfur d. Ethanol Technician A says that the use of methanol in internal combustion engines has declined over the years. Technician B says that the use of MTBE as a gasoline additive has declined over the years. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A nor B Technician A says that reformulated gasoline produces a leaner air-fuel mixture. Technician B says that RFG generates more carbon dioxide. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A nor B Technician A says that dedicated vehicles are those designed to use one particular type of fuel. Technician B says that bi-fuel vehicles can operate solely on an alcohol-based fuel or unleaded gasoline, or a mixture of the two, which gives the driver flexibility and convenience when refilling the fuel tank. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A nor B Technician A says white smoke in the exhaust of a diesel engine can be the result of a cylinder misfire in a warm engine. Technician B says blue smoke in the exhaust of a diesel engine can be caused by scored cylinder walls. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A nor B Technician A says piezo material is a type of crystal that rapidly shrinks when it is exposed to electrical current. Technician B says piezo material shrinks very slowly when current to it is stopped. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A nor B 6ASRQ While discussing chemicals that are currently added to refined gasoline in order to boost its octane: Technician A says methylcyclopentienyl manganese tricarbonyl (MMT) is normally added to gasoline. Technician B says ethanol can be added to boost the octane rating of gasoline. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A nor B While discussing common rail fuel injection systems: Technician A says the individual injectors are activated by the high pressure present in the fuel rail. Technician B says some late-model CR systems have an intensifier in the injector that allows for an increase in fuel pressure. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A nor B Technician A says diesel engines consume less fuel per mile than a gasoline engine of the same size. Technician B says diesel engines provide more torque than a gasoline engine of the same size. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A nor B While discussing the reasons why the use of E85 gasoline is good for consumers: Technician A says it is produced in the United States and can reduce our reliance on foreign oil. Technician B says an engines fuel consumption is greatly reduced. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A nor B Fuel pump is a statement of the volume of the fuel flow from the pump.Explain the purpose of the relief valve and one-way check valve in an electric fuel pump.Most fuel tank filler caps contain a pressure valve and a. a. vapor separator b. vacuum relief valve c. one-way check valve d. surge plate What type of fire extinguisher should you have close by when you are working on fuel system components?What is the first thing that should be disconnected when removing a fuel tank?Why is a plastic or metal restrictor placed in either the end of the vent pipe or in the vapor-vent hose on some vehicles?Low fuel pump pressure causes a mixture and excessive pressure causes a mixture.True or False? Fuel pressure typically is at its highest level when vacuum is applied to the pressure regulator.If fuel pump pressure or volume is less than specified, which of the following is not a likely cause of the problem? a. A restricted fuel filter b. A faulty fuel pump c. Restricted fuel return lines d. Restricted fuel supply lines Which of the following statements about a fuel volume test is not true? a. This test measures the flow rate of the pump and can help isolate fuel system restrictions or weak pumps. b. The test is conducted by collecting the fuel dispensed by the certain during a period of time, normally 5 seconds. c. The flow of fuel into the container should be smooth and continuous with no signs of air bubbles. d. Poor results may indicate a bad pump or restrictions in the delivery system.Low fuel pressure can be caused by all of the following except. a. a clogged fuel filter b. a restricted fuel line c. a fuel pump that draws too high amperage d. a dirty filter sock in the tank If a fuel system loses pressure immediately after the ignition is turned off, the possible problems are all of the following except. a. a leaking injector b. restricted fuel lines c. leaking connectors or hoses d. a faulty pressure regulator List at least five safety precautions that should be adhered to when working with fuel systems.Describe the operation of the evaporative system integrity check.True or False? On todays vehicles, an electric fuel pump runs only when the engine is running.Technician A says that excessively high pressure from an electric fuel pump can be caused by a faulty pressure regulator. Technician B says that the typical problem may be an obstructed return line. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A nor B Technician A replaces a damaged steel fuel line with one made of synthetic rubber. Technician B replaces a damaged steel fuel line with one made of steel. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A nor B While discussing electric fuel pumps: Technician A says that some electric fuel pumps are combined in one unit with the gauge sending unit. Technician B says that on an engine with an electric fuel pump, low engine oil pressure may cause the engine to stop running. Who is correct? a. Technician A only b. Technician B only c. Both A and B d. Neither A nor B To relieve fuel pressure on an EFI car: Technician A connects a pressure gauge to the fuel rail. Technician B disables the fuel pump and runs the car until it dies. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A nor B While discussing quick-disconnect fuel line fittings: Technician A says that some quick-disconnect fittings may be disconnected with a pair of snapring pliers. Technician B says that some quick-disconnect fittings are hand releasable. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A nor B While discussing fuel filters: Technician A says that on some vehicles the fuel filter is not serviceable as a regular maintenance item. Technician B says that some fuel filters are located in the fuel return lines. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A nor B While discussing the various fuel filters used in current automobiles: Technician A says that all systems have a vapor separator that prevents gaseous fuel from being sent to the fuel pump. Technician B says that fuel systems have a strainer located in the fuel tank that prevents large contaminants from entering the fuel system. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A nor B While discussing fuel tank filler pipes and caps: Technician A says that the threaded filler cap should be tightened until it clicks. Technician B says that the vent pipe is connected from the top of the filler pipe to the bottom of the fuel tank. Who is correct? a. Technician A only b. Technician B only c. Both A and B d. Neither A nor B While discussing electric fuel pumps: Technician A says that the one-way check valve prevents fuel flow from the underhood fuel system components into the fuel pump and tank when the engine is shut off. Technician B says that the one-way check valve prevents fuel flow from the pump to the fuel filter and fuel system if the engine stalls and the ignition switch is on. Who is correct? a. Technician A only b. Technician B only c. Both A and B d. Neither A nor B While discussing electric fuel pumps: Technician A says that some electric fuel pumps in EFI systems are computer controlled. Technician B says that fuel pump pressure is determined by measuring the amount of fuel that the pump will deliver in a specific length of time. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A nor B Explain the major differences between port fuel injection and gasoline direct injection systems.What is meant by sequential firing of fuel injectors?3RQ Explain how the computer controls the air-fuel ratio on an EFI system.True or False? Diesel engines require higher fuel pressures than comparably sized gasoline engines.Describe the purpose of a manifold absolute pressure (MAP) sensor.Explain the basic operation of a CSFI system.True or False? In GDI systems, the PCM controls fuel pressure through pulse width modulation of the electric high-pressure fuel pump.When the throttle plates are closed in a port injection system, where does the air needed for idle speeds come from?If the injector pulse width is increased, the air-fuel ratio becomes ____.When the engine is idling, the pressure regulator in a PFI system provides ____fuel pressure compared to the fuel pressure at wide-open throttle.Why are special fuel injectors needed for GDI systems?How does a GDI system provide for a stratified charge in the combustion chamber?How does a piezoelectric injector work?Which of the following statements about fuel trim is not true? a. A positive fuel trim value means that the PCM detects a lean mixture and is decreasing the pulse width to add more fuel to the mixture. b. Short-term fuel trim represents changes made immediately in response to HO2S signals. c. Long-term fuel trim represents changes made to set a new base pulse width. d. Long-term fuel trim responds to the trends of the short-term fuel trim.While discussing EFI systems: Technician A says that the PCM provides the proper air-fuel ratio by controlling the fuel pressure. Technician B says that the PCM provides the proper air-fuel ratio by controlling injector pulse width. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A nor B While discussing electronic fuel injection principles: Technician A says that the PCM always adjusts the air-fuel ratio in response to the signals. Technician B says that cold air is dense, which is why the PCM enriches the mixture when the engine is cold. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A nor B While discussing returnless fuel systems: Technician A says that in a returnless fuel system the pressure regulator is mounted on the fuel rail. Technician B says that in this type of fuel system the pump and pressure regulator are combined in one unit. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A nor B While discussing central port injection systems: Technician A says that CPI systems use one injector and several injector nozzles. Technician B says that CPI systems open each injector sequentially. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A nor B While discussing throttle-by-wire systems: Technician A says that a spring on the throttle shaft provides the limp-home feature. Technician B says that most systems have redundant processors and the TP and accelerator pedal sensors send redundant input signals. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A nor B While discussing the compression ratios used with engines equipped with a GDI system: Technician A says that higher ratios can be used because ignition timing is normally very advanced. Technician B says that higher ratios are possible because the small droplets of fuel injected directly into the cylinder tend to cool the mixture in the cylinder. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A nor B While discussing air-fuel ratios: Technician A says that a stoichiometric mixture is theoretically the best combination of fuel and air to provide for total combustion. Technician B says that a stoichiometric mixture always results in complete combustion. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A nor B Technician A says that air-fuel ratios can be regulated by controlling the on time of the injectors. Technician B says that the air-fuel ratio can be regulated by controlling the pressure applied to the individual injectors. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A nor B While discussing GDI systems: Technician A says that this type of system allows engines to run at very lean air-fuel ratios and at higher-than-normal compression ratios. Technician B says that GDI systems eliminate the need to have an EGR valve on the engine. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A nor B While discussing SFI systems: Technician A says that when the injection system fires according to crank- shaft position and speed, it is operating in the synchronous mode. Technician B says that one of the advantages of SFI systems is that they are always in the synchronous mode. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A nor B List four service precautions for working on the fuel injection system.What is indicated by a LTFT reading of 24 percent?What is the correct procedure for checking an oxygen sensor with a DMM?What is the difference between STFT and LTFT?The PCM checks for a closed throttle plate each time the engine starts. This becomes the base for all throttle settings and can be viewed by looking at the PID with the throttle closed. Which of the following would not cause an abnormal reading and a higher-than-normal idle speed? a. A bad TP sensor b. A bad IAC valve c. Loose or worn throttle plates d. Excessive noise in the TP or related circuits Which of the following is a likely cause of a lean condition during acceleration and cruising speeds? a. A defective oxygen sensor b. A defective PCM c. A defective ECT sensor d. A defective MAF sensor What problem may result from dirt buildup on an engines throttle plates?Which of the following would not cause a hard-to-start problem on a PFI engine? a. A defective IAC valve b. A defective oxygen sensor c. A leaking fuel pressure regulator d. Dirty injectors What is the correct way to test an injector with an ohmmeter?What is the difference between the pulse width and the duty cycle of an injector?How can you use a dual trace scope to make sure that the injectors are firing at the correct time?What are three possible problems that can allow fuel pressure to rapidly bleed down once the engine is shut off?What is the purpose of having two accelerator pedal signals in an electronic throttle control system?What is indicated by a negative LTFT value?True or False? The signals from an air-fuel ratio sensor are identical to those from a conventional oxygen sensor.While discussing the causes of higher-than-specified fuel pressure: Technician A says that a leaking fuel pressure regulator on a PFI system may cause high fuel pressure. Technician B says that if the FRP sensor voltage signal is higher than specified, fuel pressure may be higher than normal. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A nor B While discussing IAC valve diagnosis: Technician A says that on some vehicles, a jumper wire may be connected to specific DLC terminals to check the IAC valve operation. Technician B says that if the scan tester indicates zero IAC valve counts, there may be an open circuit between the PCM and the IAC valve. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A nor B While discussing IAC motor removal, service, and replacement: Technician A says that throttle body cleaner may be used to clean the IAC motor internal components. Technician B says that on some vehicles, IAC motor damage occurs if the pintle is extended more than specified during installation. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A nor B While discussing injector testing: Technician A says that a defective injector may cause cylinder misfiring at idle speed. Technician B says that restricted injector tips may result in acceleration stumbles. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A nor B While discussing airflow sensors: Technician A says that with mass airflow and volume airflow sensor systems, if any air bypasses the sensors, the engine will run lean. Technician B says that vacuum leaks in a speed density system will decrease injector pulse width. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A nor B While discussing scan tool diagnosis of fuel injection systems: Technician A says that the scan tool may allow for control over some systems and components on many systems. Technician B says that many scan tools will store sensor readings during a road test and then play back the results in a snapshot test mode. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A nor B While discussing a high idle speed problem: Technician A says that higher-than-normal idle speed may be caused by low electrical system voltage. Technician B says that higher-than-normal idle speed may be caused by a defective coolant temperature sensor. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A nor B While discussing the causes of a rich air-fuel ratio: Technician A says that a rich air-fuel ratio may be caused by a faulty fuel rail pressure sensor. Technician B says that a rich air-fuel ratio may be caused by a defective coolant temperature sensor. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A nor B While diagnosing an idle speed problem: Technician A says that higher-than-normal TP signals at idle will cause the IAC to close, which will decrease idle speed. Technician B says that if the resistance of the ECT is too low, a lower-than-normal voltage signal is sent to the PCM, which interprets this as a hot engine and will close the IAC to decrease speed. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A nor B While looking at fuel trim values: Technician A says that restricted or dirty injectors may be evident by a negative LTFT. Technician B says that a faulty fuel pressure regulator may result in a negative LTFT. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A nor B What is the difference between psia and psig readings?What can be used to check for a restricted exhaust system?A mini-converter is used _____. a. on small vehicles where a normal converter will not fit properly b. on engines that use leaded fuels c. in conjunction with EGR systems to supply clean exhaust for the cylinders d. to reduce emissions during engine warmup True or False? Engine misfires can cause a catalytic converter to overheat.What is acoustic supercharging?Describe the basic operation of an intake manifold runner control (IMRC) system.7RQ True or False? All wastegates are controlled by the PCM.9RQ A restricted exhaust system can cause______. a. stalling b. loss of power c. backfiring d. all of the above Which of the following is not characteristic of a supercharger? a. It is used to increase engine power by compressing the air that goes into the combustion chambers. b. It usually is located close to the exhaust manifold. c. It utilizes a belt-driven pulley. d. It requires a mechanical connection between the engine and the pressurizing pump to compress the intake gases.Ten psi of turbo boost means that air is being fed into the engine at_______ when the engine is operating at sea level. a. 4.7 psia b. 10 psia c. 14.7 psia d. 24.7 psia What manages turbo output by controlling the amount of exhaust gas entering the turbine housing? a. Wastegate b. Turbine seal assembly c. Turbine d. Compressor What is the first step in turbocharger inspection? a. Check the air cleaner for a dirty element. b. Open the turbine housing at both ends. c. Start the engine and listen to the system. d. Remove the ducting from the air cleaner to the turbo and examine the area.15RQ Technician A says that a turbocharger has its own self-contained lubrication system. Technician B says that a turbocharger should not be operated when the engines oil pressure is lower than 30 psi. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A nor B Technician A makes sure that the exhaust system is cool to the touch before working on it. Technician B disconnects the batterys negative cable before welding an exhaust pipe. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A nor B Technician A says vacuum refers to any pressure that is greater than atmospheric pressure. Technician B says vacuum changes based on altitude. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A nor B Technician A uses sandpaper to remove carbon deposits from turbocharger wastegate parts. Technician B scrapes off heavy deposits before attempting to clean the unit. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A nor B Technician A says that a vacuum leak results in less air entering the engine, which causes a richer air-fuel mixture. Technician B says that a vacuum leak can cause the engine to run poorly. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A nor B Technician A says that vacuum hose routing for the entire vehicle is illustrated on the underhood decal. Technician B says that this decal illustrates emission system vacuum hose routing. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A nor B Before replacing any exhaust system component: Technician A soaks all old connections with penetrating oil. Technician B checks the old systems routing for critical clearance points. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A nor B A vehicles intake manifold is warped: Technician A says the manifold may need to be replaced. Technician B says the manifold may be able to be resurfaced flat. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A nor B Technician A says that the catalytic converter is used only to quiet the noise of the exhaust. Technician B says that the catalytic converter is used to alter the contents of the engines exhaust. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A nor B Technician A says that the exhaust manifold gasket seals the joint between the exhaust manifold and the exhaust pipe. Technician B says that a resonator helps to reduce exhaust noise. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A nor B Explain why a small PCV valve opening is adequate at idle speed.At what temperature do nitrogen atoms combine with oxygen atoms to form NOx?Describe the operation of a digital EGR valve.Name the three types of emissions being controlled in gasoline engines.The PCV system prevents from escaping to the atmosphere.In a negative backpressure EGR valve, if the exhaust pressure passage in the stem is plugged, the bleed valve remains.Describe how a selective catalytic reduction system works.HC emissions may come from the tailpipe or sources.What types of catalyst are typically used to reduce NOx and to oxidize HC and CO?Why is a PCV system critical to an engines durability?Which of the following systems is designed to reduce NOx and has little or no effect on overall engine performance? a. PCV b. EGR c. AIR d. EVAP What is a catalyst?Rather then rely on the AIR system for extra oxygen in a TWC, what do most late model vehicles do to support the oxidation process?Which of the following statements about carbon dioxide is not true? a. CO2, levels are highest when the air-fuel ratio is slightly leaner than stoichiometric. b. The production of CO2, is directly related to the amount of fuel consumed; therefore, more fuel efficient engines produce less CO2. c. To reduce CO2, levels in the exhaust, engineers are working hard to decrease fuel consumption to keep CO2 low. d. The concern for CO2 emissions is one of the primary reasons for the delayed use of alternative fuels for automobiles.Why do the EGR systems on many late-model diesel vehicles include an EGR cooler?While discussing PCV valve operation: Technician A says that the PCV valve opening is decreased at part-throttle operation compared to idle operation. Technician B says that the PCV valve opening is decreased at wide-open throttle compared to part throttle. Who is correct? a. Technician A only b. Technician B only c. Both A and B d. Neither A nor B While discussing EGR systems with a differential pressure feedback electronic (DPFE) sensor: Technician A says that the DPFE sensor sends a signal to the PCM in relation to intake manifold pressure. Technician B says that the PCM corrects the EGR flow if the actual flow does not match the requested flow. Who is correct? a. Technician A only b. Technician B only c. Both A and B d. Neither A nor B While discussing evaporative (EVAP) systems: Technician A says that the coolant temperature has to be above a preset value before the PCM will operate the canister purge solenoid. Technician B says that the vehicle speed has to be above a preset value before the PCM will operate the canister purge solenoid. Who is correct? a. Technician A only b. Technician B only c. Both A and B d. Neither A nor B Technician A says that an EGR valve that is stuck open can cause idle problems. Technician B says that a stuck closed EGR can increase HC emissions. Who is correct? a. Technician A only b. Technician B only c. Both A and B d. Neither A nor B While discussing SCR systems: Technician A says that they are used in place of a conventional catalytic converter to reduce NOx, CO, and HC. Technician B says that the most common reductant used is SCR systems is an ammonia-like substance called urea. Who is correct? a. Technician A only b. Technician B only c. Both A and B d. Neither A nor B While discussing automotive emissions: Technician A says that oxygen emissions are monitored because they are an indication of the completeness of the combustion process. Technician B says that the conditions for minimizing HC emissions are the same as those that cause high NOx emissions. Who is correct? a. Technician A only b. Technician B only c. Both A and B d. Neither A nor B Technician A says that during oxidation, as NOx gases pass over the catalyst, the N atoms are pulled from the NOx molecules and are absorbed by the catalyst. The released oxygen atoms then flow through the converter to the second bed. The result of NOx oxidation is pure nitrogen plus oxygen or carbon dioxide. Technician B says that during the reduction phase inside the converter, hydrocarbon and carbon monoxide molecules experience a second combustion. The result of this combustion or oxidation process is water vapor and carbon dioxide. Who is correct? a. Technician A only b. Technician B only c. Both A and B d. Neither A nor B While discussing PCV systems without a PCV valve: Technician A says that blowby gases are routed into the intake manifold through a fixed orifice tube. The system works the same as if it had a valve, except that the system is regulated only by the vacuum at the orifice and the size of the orifice. Technician B says that VVT systems eliminate the need for a PCV system. Who is correct? a. Technician A only b. Technician B only c. Both A and B d. Neither A nor B While diagnosing the cause of high HC and O2 emissions: Technician A says that the HC may be elevated because of an ignition problem. Technician B says that the O2 may be elevated because of an ignition problem. Who is correct? a. Technician A only b. Technician B only c. Both A and B d. Neither A nor B While discussing electric exhaust gas recirculation (EEGR) systems: Technician A says that some are air cooled. Technician B says that some are cooled by engine coolant. Who is correct? a. Technician A only b. Technician B only c. Both A and B d. Neither A nor B A rich air-fuel ratio causes HC emissions to ________.What will result from too little EGR flow? And what can cause a reduction in the flow?What can result from a charcoal canister that is filled with liquid or water?What happens if a PCV valve is stuck in the open position?Explain why the I/M 240 and similar tests are being replaced by the OBD II system test.How do you test the efficiency of a secondary AIR system?True or False? No-start, surging, or stalling can be caused by an EGR valve that does not open.List five common causes for high HC emissions.Describe carbon monoxide (CO) emissions in relation to air-fuel ratio.A restricted catalytic converter can cause all of the following except. a. stalling after the engine starts b. popping or backfiring through the intake manifold c. a drop in engine vacuum d. increased power at high speeds Which of the following statements about EVAP systems is not true? a. If the system is purging vapors from the charcoal canister when the engine is running at high speeds, rough engine operation will occur. b. Cracked hoses or a canister saturated with gasoline may allow gasoline vapors to escape to the atmosphere, resulting in gasoline odor in and around the vehicle. c. Rough idle, flooding, and other similar conditions can indicate a saturated canister. d. A vacuum leak in the system can cause starting and performance problems.As a catalytic converter begins to deteriorate, the signal from the postcatalyst HO2S becomes the signal of the precatalyst HO2 S. a. shorter than b. more like c. larger than d. flatter than How much pressure does a typical EVAP pressure tester apply to the system during testing? a. 14 in. Hg b. 14 psi c. 1 in. H2O d. 0.5 psi Which of the following exhaust gases is typically not measured during an I/M 240 test? a. HC b. O2 c. NOx d. CO 15RQ While discussing the proper way to test a catalytic converter: Technician A says that a pressure gauge can be inserted into the oxygen sensor bore and the backpressure caused by the converter measured. Technician B says that restrictions in the converter can be checked with a vacuum gauge while the engine is being quickly accelerated. Who is correct? a. Technician A only b. Technician B only c. Both A and B d. Neither A nor B 2ASRQ While discussing catalytic converter diagnosis: Technician A says that Mode $06 data should be checked. Technician B says that a good converter is evident by low amounts of CO2 in the exhaust. Who is correct? a. Technician A only b. Technician B only c. Both A and B d. Neither A nor B While discussing EGR valve diagnosis: Technician A says that if the EGR valve does not open, the engine may hesitate on acceleration. Technician B says that if the EGR valve does not open, the engine may detonate on acceleration. Who is correct? a. Technician A only b. Technician B only c. Both A and B d. Neither A nor B While discussing EGR valve diagnosis: Technician A says that a defective throttle position sensor may affect the EGR valve operation. Technician B says that a defective engine coolant temperature (ECT) sensor may affect the EGR valve operation. Who is correct? a. Technician A only b. Technician B only c. Both A and B d. Neither A nor B When discussing the diagnosis of a positive back pressure EGR valve: Technician A says that with the engine running at idle speed, if a hand pump is used to supply vacuum to the EGR valve, the valve should open at 12 in. Hg of vacuum. Technician B says that with the engine not running, any vacuum supplied to the EGR valve should be bled off and the valves diaphragm should not move. Who is correct? a. Technician A only b. Technician B only c. Both A and B d. Neither A nor B While diagnosing a PCV problem: Technician A says that a stuck open PCV valve will cause a richer than normal air-fuel mixture. Technician B says that oil in the air cleaner assembly can be caused by worn piston rings. Who is correct? a. Technician A only b. Technician B only c. Both A and B d. Neither A nor B Technician A says that the AIR system should pump air into the exhaust manifold(s) during engine warmup. Technician B says that the secondary air system check valve can be checked with an exhaust gas analyzer. Who is correct? a. Technician A only b. Technician B only c. Both A and B d. Neither A nor B While discussing PCV system diagnosis: Technician A says that a defective PCV valve may cause rough idle operation. Technician B says that satisfactory PCV system operation depends on a properly sealed engine. Who is correct? a. Technician A only b. Technician B only c. Both A and B d. Neither A nor B While discussing EVAP testing: Technician A says that most OEMs recommend that clean, high-pressure shop air be used to pressurize the system to test for leaks. Technician B says that nitrogen is typically used to drive the smoke through the system when checking the system with a smoke machine. Who is correct? a. Technician A only b. Technician B only c. Both A and B d. Neither A nor B What are the basic components of a belt alternator starter hybrid system?What are the main reasons that a mild hybrid consumes less fuel than a conventional vehicle?Which of the following statements about the high-voltage circuits in a Honda Hybrid is NOT true? a. All of the high-voltage cables are covered in orange sleeves for easy identification. b. You should always follow the disarming of the high-voltage systems before performing any service work on or near the high-voltage circuits. c. There is a main switch on the instrument panel that is used to disconnect the battery module from the rest of the car. d. There are three large capacitors in the MDM that will take at least 5 minutes to discharge after the switch is turned off.The Prius PHEV offers many advantages over the basic Prius, how is that possible?In a Toyota Prius, what members of the planetary gearset are connected to the motor/generators and the engine?6RQ 7RQ 8RQ After isolating the high-voltage system, what is the minimum time you should wait before beginning to work on or around the hybrid system? a. 1 hour b. 30 minutes c. 15 minutes d. 5 minutes How often must insulated linemans gloves be tested and recertified?Nearly all hybrids have less powerful engines than typical non-hybrids. What feature of a hybrid provides power to allow the engine to overcome heavy loads?What is the purpose of a typical inverter?On hybrids with a separate cooling system for the inverter and other electronics, what needs to happen if air is trapped in the cooling system?During diagnostics, the DTC P3009 is displayed, what does this indicate?Which of the following is the least likely to decrease fuel consumption of a hybrid vehicle? a. Low-rolling resistance tires b. Increased aerodynamic drag c. Stop-start systems d. Lighter and less powerful engines 1ASRQ When working on a high-voltage system, it is best to keep anyone who is not part of the service away from you and the car by creating a buffer zone around the car. Technician A makes sure the outside edges of the zone are at least one foot away from the car. Technician B places orange cones to define the outer boundaries of the zone. Who is correct? a. Technician A only b. Technician B only c. Both A and B d. Neither A nor B 3ASRQ Technician A says diesel engines can be used in a hybrid powertrain. Technician B says a gasoline engine is normally used in hybrid powertrain. Who is correct? a. Technician A only b. Technician B only c. Both A and B d. Neither A nor B While discussing working on hybrid vehicles: Technician A says to make sure that the high-voltage system is shut down and isolated from the vehicle before working near or with any high-voltage component. Technician B says that when working on or near the high-voltage system, even when it is de-powered, always use insulated tools. Who is correct? a. Technician A only b. Technician B only c. Both A and B d. Neither A nor B 6ASRQ 7ASRQ Technician A says PVE refrigerant oil is commonly recommended for electric A/C compressors. Technician B says PAG refrigerant oil can be used in many electric A/C compressors. Who is correct? a. Technician A only b. Technician B only c. Both A and B d. Neither A nor B 9ASRQ 10ASRQ Why are carbon dioxide emissions a concern?List five things a driver of a BEV can do to extend the driving range of the vehicle.What makes up the propulsion system in a BEV?What basic factors affect the required time to recharge the battery pack in a BEV?There are two basic ways a BEV is connected to an external source of electricity for charging: conductive and inductive. What is the difference between the two?Explain what the ratings of kilowatts and kilowatt hours mean.True or False? All fuel cell vehicles have regenerative braking and 12-volt auxiliary systems.Which of the statements about hydrogen is true? a. A hydrogen atom is one proton and two electrons. b. Hydrogen is one of the heaviest elements known and is full of energy. c. Fossil fuels are combinations of carbon and hydrogen. d. Hydrogen is produced in a fuel cell when water is broken down into its basic elements.True or False? A PEM fuel cell needs to operate at very high temperatures.Why is water control so important to the effectiveness of a PEM fuel cell?Which of the following CANNOT be used as a source for the production of hydrogen? a. Gasoline b. Methanol c. Carbon dioxide d. Natural gas Which of the following statements about fuel cells is NOT true? a. A single fuel cell produces very low voltage, normally less than one volt. b. A fuel cell produces electricity through an electro-chemical reaction that combines hydrogen and oxygen to form water. c. A fuel cell is composed of two electrodes coated with a catalyst and separated from each other by an electrolyte and from the case by separators. d. In a fuel cell, catalysts are used to ignite the hydrogen; this causes a release of electrons or electrical energy.What is the basic fuel for a fuel cell? a. Hydrogen b. Methanol c. Electricity d. Gasoline The component that changes the molecular structure of hydrocarbons into hydrogen-rich gas is called a. a. pressure container b. fuel cell c. fuel injector d. reformer Which of the following statements about hydrogen is not true? a. Hydrogen displaces air, so any release in an enclosed space could cause asphyxiation. b. Hydrogen must be stored as a compressed gas. c. Hydrogen is nontoxic. d. Hydrogen is highly flammable and there is risk for an explosion.Technician A says power is the ability to do work. Technician B says energy is the rate at which work is done. Who is correct? a. Technician A only b. Technician B only c. Both A and B d. Neither A nor B While discussing inductive charging: Technician A says most current BEVs use this system because it is safe. Technician B says this method requires that a weatherproof paddle be inserted into the vehicles charge port. Who is correct? a. Technician A only b. Technician B only c. Both A and B d. Neither A nor B Technician A says some BEVs use liquid to heat the passenger compartment. Technician B says some BEVs use an electric resistance heater with a fan to heat the passenger compartment. Who is correct? a. Technician A only b. Technician B only c. Both A and B d. Neither A nor B While discussing charger connections: Technician A says nearly all BEVs currently sold in North America have an AVCON connector. Technician B says the connector currently used for DC fast charging on the Nissan Leaf and Mitsubishi i vehicles is based on the CHAdeMO standard. Who is correct? a. Technician A only b. Technician B only c. Both A and B d. Neither A nor B Technician A says that a fuel cell produces electricity through an electrochemical reaction that combines hydrogen and oxygen to form water. Technician B says that in a fuel cell, catalysts are used to ignite the hydrogen, causing a release of electrons or electrical energy. Who is correct? a. Technician A only b. Technician B only c. Both A and B d. Neither A nor B While diagnosing the control system of a BEV: Technician A begins by checking the voltage of the auxiliary battery. Technician B inspects all fuses, fusible links, wiring harness, connectors, and ground in the low-voltage circuit. Who is correct? a. Technician A only b. Technician B only c. Both A and B d. Neither A nor B 7ASRQ Technician A says that all FCEVs have regenerative braking. Technician B says that all FCEVs have an auxiliary 12-volt battery. Who is correct? a. Technician A only b. Technician B only c. Both A and B d. Neither A nor B Technician A says that gasoline can be used as a source of hydrogen for a fuel cell. Technician B says that carbon dioxide can be used as a source of hydrogen for a fuel cell. Who is correct? a. Technician A only b. Technician B only c. Both A and B d. Neither A nor B While discussing hydrogen: Technician A says that a hydrogen atom has one proton and two electrons. Technician B says that hydrogen is produced in a fuel cell when water is broken down into its basic elements. Who is correct? a. Technician A only b. Technician B only c. Both A and B d. Neither A nor B Name two types of friction facings.True or False? If the fluid reservoir for a hydraulic clutch is low, the entire system should be checked for fluid leaks.What is another name for the diaphragm spring?Name three types of clutch linkages.What is used to measure clutch pedal play?The clutch, or friction, disc is connected to the. a. engine crankshaft b. transmission input shaft c. transmission output shaft d. transmission countershaft Torsional coil springs in the clutch disc_____. a. cushion the driven disc engagement rear to front b. are the mechanical force holding the pressure plate against the driven disc and flywheel c. absorb the torque forces d. are located between the friction rings The pressure plate moves away from the flywheel when the clutch pedal is.Which of the following is probably not the cause of a vibrating clutch? a. Excessive crankshaft end play b. Out-of-balance pressure plate assembly c. Excessive flywheel runout d. Loose flywheel bolts When the clutch pedal is released on a hydraulic clutch linkage, the______. a. master cylinder piston is released by spring tension b. master cylinder piston is released by hydraulic pressure c. slave cylinder is released by hydraulic pressure d. slave cylinder piston does not move

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