Diag PreTest

Lakukan tugas rumah & ujian kamu dengan baik sekarang menggunakan Quizwiz!

On European vehicles equipped with twinchargers, the turbocharger boosts power at low speeds and the supercharger boosts power at high speeds. a. True b. False

b. False *

Beginning with model year 2008, what type of communication protocol is required for diagnostics? a. Class-A (UART) b. Class-B (SAE J-1850) c. Class-C (CAN) d. Class-D (SAE J-1761)

c. Class-C (CAN)

Technician A says HC emissions are caused by incomplete combustion. Technician B says an excessively lean air/fuel mixture may result in cylinder misfiring and high HC emissions. Who is correct? a. A only b. B only c. both A and B d. neither A nor B

c. both A and B

Technician A says a loose ignition module mount can cause intermittent misfires or no-start conditions. Technician B says when installing a new ignition module, a small amount of heat conductive grease should be applied to the mounting surfaces. Who is correct? a. A only b. B only c. both A and B d. neither A nor B

c. both A and B

Technician A says high engine temperatures reduce HC and CO emissions. Technician B says incorrect ignition timing can increase the production of NOX.Who is correct? a. A only b. B only c. both A and B d. neither A nor B

c. both A and B

Technician A says there is maximum EGR flow only when the vehicle is at a cruising speed with a very light load. Technician B says instead of an EGR valve many late-model engines use variable valve timing (VVT) to trap some exhaust gases in the combustion chamber. Who is correct? a. A only b. B only c. both A and B d. neither A nor B

c. both A and B *

IAC (idle air control) valves are operated by a ______. a. vacuum servo b. reversible DC electric motor c. stepper motor d. All the answers are correct.

c. stepper motor *

An engine coolant temperature sensor is an example of a(n) ______. a. potentiometer b. actuator c. thermistor d. Wheatstone bridge

c. thermistor

Which of the following is a cause of detonation? a. a disconnected EGR valve vacuum line b. a leaking EGR valve diaphragm c. the EGR valve stuck in the closed position d. All the answers are correct.

d. All the answers are correct. *

Which of the following is NOT connected to the tone generator? a. headlight switch b. ignition key switch c. seat belt switch d. park/neutral safety switch

d. park/neutral safety switch

Excessive Hydrocarbons (HC) - Ignition misfire Excessive Carbon monoxide (CO) -Leaking fuel injector Excessive HC and CO - Engine oil diluted with gasoline Lower than normal oxygen (O2) - Rich air fuel mixture Higher than normal oxides of nitrogen (NOx) - Defective EGR system Higher than normal HC, O2, and NOx - A false signal from the O2 sensor

Feul Gauge Erratic - Sticking Gauge Sender Odometer Error - Inoperative memory module digital display dnl - blown fuse speedo stay 0 - faulty wiring speed wrong - tires

LIN BUS - Single wire serial date network CLASS B - Medium CLASS C - High CLASS A - Low CAN BUS - Network with gateway MOST BUS - Media

Vacuum leaks in speed density systems can be verified by watching the _____ on a scan tool. a. O2 sensor cycle b. IAC counts c. mass airflow (MAF) voltage d. delta EGR (exhaust gas recirculation)

a. O2 sensor cycle *

Which of the following is NOT an actuator? a. PCV valve b. fuel injector c. canister purge solenoid d. idle air control valve

a. PCV valve *

A throttle position sensor has ______. a. a 5-volt reference input terminal b. a 0- to-5-volt signal output terminal c. a ground terminal d. All the answers are correct.

a. a 5-volt reference input terminal *

Which of the following requires a high-speed bus? a. antilock brakes b. windshield wipers c. power windows d. horn

a. antilock brakes

The rain sensor in an automatic windshield wiper system is located ______. a. at the top/center of the windshield b. in the grill c. inside the drivers side rear view mirror d. in the dash pad (above instrument panel)

a. at the top/center of the windshield`

Ignition spark typically occurs a few degrees _______. a. before top dead center (BTDC) b. after top dead center (ATDC) c. before bottom dead center (BBDC) d. after bottom dead center (ABDC)

a. before top dead center (BTDC) *

Which of the following is not a type voltage generating sensor? a. coolant temperature sensor (CTS) b. oxygen sensor c. knock sensor d. magnetic pulse (PM) generator

a. coolant temperature sensor (CTS) *

What sensor is used to detect engine misfire? a. crankshaft position b. knock c. cylinder head temperature d. exhaust gas temperature

a. crankshaft position

An accelerator pedal position sensor (APP) is used on vehicles equipped with ______. a. electronic throttle control b. cruise control c. torque converter clutch (TCC) d. All the answers are correct.

a. electronic throttle control

Which of the following is not a common cause of preignition? a. faulty ignition coil b. incandescent carbon deposits in the combustion chamber c. faulty cooling system d. too hot of a spark plug

a. faulty ignition coil *

Which of the following would not cause the fuel pressure to drop to zero immediately after engine shut down? a. leaking pressure regulator vacuum line b. leaking fuel pressure regulator c. leaking fuel pump check valve d. leaking fuel injector

a. leaking pressure regulator vacuum line

Which of the following sensors is NOT used by the computerized ignition system to control ignition timing? a. oxygen sensor b. engine temperature c. manifold vacuum d. engine RPM

a. oxygen sensor

The internal combustion engine in a hybrid does not normally run when the vehicle is at a standstill. What alerts the driver that the vehicle is capable of being driven? a. the Ready light b. the Hybrid System On light c. the Electric Drive Enabled light d. the Drive light

a. the Ready light

A digital EGR valve has up to _____ solenoids. a. three b. four c. six d. eight

a. three *

A horn can be tested by connecting a jumper wire between the battery positive terminal and the horn power terminal. a. True b. False

a. True

A twin scroll turbocharger uses two turbine wheels connected to a common shaft to improve performance and reduce lag. a. True b. False

a. True

Acoustic supercharging uses the pressure of the air bouncing back and forth between the closed intake valve and incoming air from the plenum to increase the amount of air drawn into the cylinders. a. True b. False

a. True

Detonation can cause physical damage to the pistons, valves, bearings, and spark plugs. a. True b. False

a. True

Higher compression ratios tend to speed up combustion. a. True b. False

a. True

In some hybrids, regeneration begins as soon as the driver's foot leaves the accelerator. a. True b. False

a. True

Insufficient timing advance or retarded timing at higher engine speeds could cause hesitation and poor fuel economy. a. True b. False

a. True

Mode 6 data show the results of the monitor diagnostic tests. a. True b. False

a. True

On some new engine designs, the exhaust manifold is incorporated into the cylinder head to increase the efficiency of the driving the turbine. a. True b. False

a. True

Piezoelectric materials can emit a small amount of voltage when they are struck, squeezed, or exposed to vibration. a. True b. False

a. True

The higher the altitude, the lower the atmospheric pressure. a. True b. False

a. True

The most widely used gasoline oxygenate additive is ethanol (ethyl alcohol). a. True b. False

a. True

Catalytic converter monitors are being discussed. Technician A says that if the converter is working, the downstream signal frequency should mirror the upstream sensor. Technician B says that the downstream sensor should provide a low-frequency voltage signal. Who is correct? a. A only b. B only c. both A and B d. neither A nor B

b. B only

Technician A says if a lean condition caused by a vacuum leak, restricted injectors, dirty MAF, clogged fuel filter, or bad fuel pump exists, the LTFT will have a negative number. Technician B says when the O2 sensor has a rich signal, the STFT goes lean to adjust the air/fuel ratio. Who is correct? a. A only b. B only c. both A and B d. neither A nor B

b. B only

Carbon monoxide is being discussed. Technician A says as the air/fuel ratio becomes richer, the CO levels decrease. Technician B says CO is a colorless, odorless, and highly poisonous gas that can cause death. Who is correct? a. A only b. B only c. both A and B d. neither A nor B

b. B only *

Technician A says the emission vacuum schematic for the vehicle can only be found in the factory service manual. Technician B says an emissions vacuum schematic is given on a decal under the hood. Who is correct? a. A only b. B only c. both A and B d. neither A nor B

b. B only *

Technician A says the oxygen sensor (O2S) detects misfires by monitoring the amount of unburned fuel in the exhaust system. Technician B says a heating element inside the sensor allows the sensor to reach operating temperature quickly and to maintain its temperature during periods of idling or low engine load. Who is correct? a. A only b. B only c. both A and B d. neither A nor B

b. B only *

Technician A uses a low-impedance test light to check for an injector pulse. Technician B uses a noid light to check the injector pulse. Who is correct? a. A only b. B only c. both A and B d. neither A nor B

b. B only *

While discussing EGR systems with a differential pressure feedback EGR (DPFE) sensor, Technician A says the DPFE sensor sends a signal to the PCM in relation to intake manifold pressure. Technician B says the PCM can make corrections to the EGR flow if the actual flow does not match the desired flow. Who is correct? a. A only b. B only c. both A and B d. neither A nor B

b. B only *

Which sensor synchronizes the firing of the injectors and determines when piston number 1 is on the compression stroke? a. CKP (crankshaft position sensor) b. CMP (camshaft position sensor) c. TPS (throttle position sensor) d. VSS (vehicle speed sensor)

b. CMP (camshaft position sensor) *

An NTC thermistor is used in a(n) _____. a. oil pressure sending unit b. engine coolant temperature sensor c. fuel gauge sending unit d. all answers are correct

b. engine coolant temperature sensor *

Which of the following components is part of both the primary and secondary ignition circuits? a. spark plugs b. ignition coil c. battery d. ignition switch

b. ignition coil *

Leaner 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

b. increase the electrical resistance inside the cylinder and increase the required firing voltage

Which of the following is NOT a component of the Toyota hybrid transaxle? a. motor/generators 1 and 2 b. multiple disc clutch c. planetary gear set d. differential assembly

b. multiple disc clutch

Modern ignition cables contain carbon fiber cores that act as a(n) ____ in the secondary circuit to cut down on radio and television interference and reduce spark plug wear. a. insulator b. resistor c. semiconductor d. heat shield

b. resistor

When a diode is _____ current cannot flow through it. a. forward biased b. reverse biased c. excited d. grounded

b. reverse biased

Semiconductors are made of ______. a. gallium b. silicon c. copper d. None of the answers is correct.

b. silicon *

Electronic odometer display readings are stored in the computer's RAM. a. True b. False

b. False

HEV air-conditioning systems are identical to those used in a conventional vehicle. a. True b. False

b. False

Most tachometers operate from a cable driven by the engine's distributor or camshaft. a. True b. False

b. False

The MAP sensor used on a turbocharged engine is calibrated the same as a MAP sensor for a nonturbocharged engine. a. True b. False

b. False

A thermistor is a temperature-variable transistor. a. True b. False

b. False *

The ideal air/fuel or stoichiometric ratio for a gasoline engine is approximately _____ pounds of air mixed with 1 pound of gasoline. a. 12 to 13 b. 14.1 c. 14.7 d. 15 to 16

c. 14.7

OBD II technology is being discussed. Technician A says the OBD II system has the ability to store a freeze frame (snapshot) of the operating conditions that existed when the fault occurred. Technician B says vehicle identification must be transmitted automatically to the scan tool. Who is correct? a. A only b. B only c. Both A and B d. Neither A nor B

c. Both A and B

Which of the following gases is NOT considered to be harmful? a. HC b. CO c. O2 d. NOX

c. O2

EGR monitors are being discussed. Technician A says some EGR system monitors EGR flow by measuring the difference in pressure as the EGR gas flows through an orifice (restriction). Technician B says some EGR monitors measure the temperature of the EGR outlet to determine whether there is gas flowing through the EGR valve. Who is correct? a. A only b. B only c. both A and B d. neither A nor B

c. both A and B

Ignition coils are being discussed. Technician A says the primary coil is normally composed of 100 to 200 turns of 20-gauge wire. Technician B says the secondary coil consists of 15,000 to 25,000, or more, turns of very fine copper wire. Who is correct? a. A only b. B only c. both A and B d. neither A nor B

c. both A and B

In EI systems using one ignition coil for every two cylinders, Technician A says two plugs fire at the same time, with one wasting the spark on the exhaust stroke. Technician B says one plug fires in the normal direction and the other in reversed polarity. Who is correct? a. A only b. B only c. both A and B d. neither A nor B

c. both A and B

None of the gauges work on a vehicle. Technician A says the connection to the instrument cluster may be open. Technician B says the cluster's IVR may be open. Who is correct? a. A only b. B only c. both A and B d. neither A nor B

c. both A and B

Oxygen sensor monitors are being discussed. Technician A says the system monitors the sensor response time as the system cycles lean-rich-lean. Technician B says that at certain times the monitor varies the fuel delivery and checks for heated oxygen sensor response. Who is correct? a. A only b. B only c. both A and B d. neither A nor B

c. both A and B

Resistor-type spark plugs are being discussed. Technician A says the resistor increases the plug firing voltage. Technician B says the resistor helps reduce radio frequency interference (RFI), which can interfere with, or damage, radios, computers, and other electronic accessories, such as GPS systems. Who is correct? a. A only b. B only c. both A and B d. neither A nor B

c. both A and B

Technician A tests an MAF sensor with a scan tool by watching for erratic changes in flow while the engine idles. Technician B checks an MAF sensor by tapping it lightly with the handle of a screwdriver while watching the waveform on a lab scope. Who is correct? a. A only b. B only c. both A and B d. neither A nor B

c. both A and B

Technician A touches a good ground immediately before touching a computer module. Technician B wears a grounding wrist strap before touching the computer electrical connections and computer case. Who is correct? a. A only b. B only c. both A and B d. neither A nor B

c. both A and B

The reasons for slower than normal wiper operation are being discussed. Technician A says the problem may be in the mechanical linkage. Technician B says there may be excessive resistance in the electrical circuit. Who is correct? a. A only b. B only c. both A and B d. neither A nor B

c. both A and B

Which of the following is associated with voltage frequency? a. cycle b. hertz c. both A and B d. neither A nor B

c. both A and B

Semiconductors are being discussed. Technician A says a semiconductor can be used as a conductor. Technician B says a semiconductor can be used as an insulator. Who is correct? a. A only b. B only c. both A and B d. neither A nor B

c. both A and B *

Technician A says a pressure gauge can be inserted into the oxygen sensor bore, and back pressure caused by the catalytic converter can be measured. Technician B says a vacuum gauge can be used to identify a restricted converter. Who is correct? a. A only b. B only c. both A and B d. neither A nor B

c. both A and B *

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. A only b. B only c. both A and B d. neither A nor B

c. both A and B *

Technician A says the action of the wastegate is controlled directly by manifold pressure. Technician B says the wastegate is controlled by the PCM. Who is correct? a. A only b. B only c. both A and B d. neither A nor B

c. both A and B *

If the throttle is held wide open while the engine is cranked over by the starter motor, the fuel management system will enter _____ mode. a. closed loop b. open loop c. clear flood d. maximum fuel delivery

c. clear flood

Excessively high CO emissions may be caused by a ______. a. lean air/fuel mixture b. missing air filter c. higher than normal fuel pressure d. All the answers are correct.

c. higher than normal fuel pressure *

A sudden increase in TP voltage tells the PCM to _____ to prevent hesitation and stumbling during acceleration. a. advance base ignition timing b. retract the IAC valve pintle c. momentarily enrich the mixture d. open the EGR valve

c. momentarily enrich the mixture

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. breaker points

c. spark plugs

A restricted catalytic converter may cause ______. a. loss of power at high speeds b. stalling after starting c. a drop in engine vacuum as engine rpm increases d. All the answers are correct.