Final Exam Aut-181 Engien Performance 1
Which of the following is NOT a spark plug thread diameter? Select one: a. 12 mm b. 14 mm c. 18 mm d. 9/16 in.
9/16 in.
Until 1994 all ignition systems used some type of distributor.
False
A camshaft position sensor [CMP] is necessary for a waste spark type ignition system to determine which coil to fire when the engine reaches TDC.
False
Conventional ignition systems are capable of producing higher electrical energy than distributorless ignition systems.
False
Driving on a rough road can trigger the engine misfire monitor.
False
Higher-octane fuels are easier to ignite and burn faster than low-octane fuel.
False
Magnetic pulse generators produce a weak DC voltage when the teeth of the trigger wheel rotate past the pickup coil.
False
On a coil-over-plug type ignition system, a faulty coil will affect two cylinders.
False
The MAP sensor used on a turbocharged engine is calibrated the same as a MAP sensor for a nonturbocharged engine.
False
The resistance of the intake air temperature (IAT) sensor increases as air temperature increases.
False
When there is a calibration update available for an OBD-II vehicle, the old EPROM is removed from its socket in the PCM and a new EPROM with the updated software is installed in its place.
False
During a coil output test, the firing line shown on the oscilloscope pattern should exceed ______ volts. Select one: a. 12 b. 350 c. 1,200 d. 35,000
35,000
A conventional oxygen sensor needs to be heated to ________ degrees Fahrenheit before it can produce a usable signal. Select one: a. 500 b. 750 c. 1,000 d. 1,200
750
Only OBD-II equipped vehicles have a sixteen-pin DLC connector.
False
Very few newer engines are equipped with a distributor.
True
A throttle position sensor has ______. Select one: a. a 5-volt reference input terminal b. a 0- to-5-volt signal output terminal c. a ground terminal d. all answers are correct
a 5-volt reference input terminal
A bad sensor ground may cause the same symptoms as a faulty sensor.
True
A late model ignition system can supply 30,000 to 60,000 volts of electricity.
True
A misfiring spark plug can cause a false oxygen sensor reading.
True
A spark plug's ceramic core or insulator acts as a heat conductor.
True
Because air/fuel ratio sensors produce a signal only after their current output has been processed by the PCM, they cannot be tested with a voltmeter or lab scope.
True
Higher compression ratios tend to speed up combustion.
True
Most engines have a spark duration of approximately _____ milliseconds. Select one: a. 0.5 b. 1.5 c. 5.0 d. 15.0
1.5
The typical amount of secondary coil voltage required to jump the spark plug gap is ____ volts. Select one: a. 500 b. 1,000 c. 10,000 d. 50,000
10,000
Which of the following statements is NOT true? Select one: a. A conventional oxygen sensor has a minimum voltage of 0.000 volts and a maximum voltage of 1.000 volt. b. On a V-type engine, bank 1 is the side of the engine where cylinder #1 is located. c. An oxygen sensor measures the difference between the amount of oxygen inside the exhaust and the outside air. d. A conventional oxygen sensor receives a 5-volt reference voltage from the PCM.
A conventional oxygen sensor receives a 5-volt reference voltage from the PCM.
Possible causes for a no-start condition on a coil-over-plug EI engine are being discussed. Technician A says a faulty crankshaft sensor may prevent the engine from starting. Technician B says a shorted ignition coil may be the cause. Who is correct?
A only
Technician A uses the snapshot function of his scan tool to record serial data during a road test that can be transferred and displayed on a PC. Technician B uses the snapshot feature of his scan tool to record the sensor data and conditions leading up to the vehicle setting a DTC. Who is correct? Select one: a. A only b. B only c. both A and B d. neither A nor B
A only
Two technicians are discussing OBD-II monitor readiness status. Technician A says that the vehicle must be driven through a drive cycle that includes several minutes of idle, low-speed cruise, medium-speed cruise, and deceleration before all monitors can be performed. Technician B says all monitors can be performed in five minutes of fast idling. Who is correct? Select one: a. A only b. B only c. both A and B d. neither A nor B
A only
Which of the following statements is not true? Select one: a. A type A misfire can cause damage to the catalytic converter if the injector is not shut down b. A type B misfire will cause the MIL light to flash c. A type B misfire is set after detected faults in two consecutive drive cycles d. A type A misfire will set a DTC and cause the MIL light to illuminate immediately
A type B misfire will cause the MIL light to flash
Which of the following is an advantage of EI ignition? Select one: a. There are no moving parts, and therefore it requires little maintenance b. It is possible to control the ignition of individual cylinders to meet specific needs c. Mechanical timing adjustments are eliminated d. All answers are correct
All answers are correct
A technician is rebuilding an engine and notices that one tooth is missing from the crank sensor pulse ring. Technician A says the pulse ring is broken and will have to be replaced. Technician B says that missing tooth identifies when cylinder #1 is at TDC and that the missing tooth is normal. Who is correct? Select one: a. A only b. B only c. both A and B d. neither A nor B
B only
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? Select one: a. A only b. B only c. both A and B d. neither A nor B
B only
Computer-controlled ignition timing is being discussed. Technician A says when excessive wheel slippage occurs, the PCM will advance the timing to increase the torque output from the engine. Technician B says to provide smooth shifting of an automatic transmission, the PCM will temporarily retard the ignition timing to reduce the engine's torque when the transmission is beginning to change gears. Select one: a. A only b. B only c. both A and B d. neither A nor B
B only
Crankshaft sensors are being discussed. Technician A says the signal from a Hall-effect CKP cannot be used to synchronize fuel injector timing with the engine. Technician B says some early distributor ignition systems relied on photoelectric sensors to monitor crankshaft position. Who is correct? Select one: a. A only b. B only c. both A and B d. neither A nor B
B only
Diagnostic trouble codes are being discussed. Technician A says a P0442 is a manufacturer's code and means different things, depending on what manufacturer built the car. Technician B says that a P0304 code is a universal code that means the same thing no matter what manufacturer built the car. Who is correct? Select one: a. A only b. B only c. both A and B d. neither A nor B Feedback
B only
Spark plug design is being discussed. Technician A says a plug with too short a reach makes it difficult to attach the plug wire boot. Technician B says a plug with too long a reach may cause preignition. Who is correct? Select one: a. A only b. B only c. both A and B d. neither A nor B
B only
While discussing EI service, Technician A says the crankshaft sensor may be rotated to adjust the basic ignition timing. Technician B says the crankshaft sensor may be moved to adjust the clearance between the pickup coil and reluctor on some EI systems. Who is correct?
B only
Usually an engine is timed so that the number 1 spark plug fires several degrees _____. Select one: a. BTDC [before top dead center] b. ATDC [after top dead center] c. BBDC [before bottom dead center] d. ABDC [after bottom dead center]
BTDC [before top dead center]
Which of the following statements about carbon tracking is NOT correct? Select one: a. Carbon tracking may occur inside a distributor cap b. Carbon tracking indicates that high voltage has followed a low-resistance conductive path c. Carbon tracking may cause a misfire d. Carbon tracking usually occurs in the primary ignition circuit
Carbon tracking usually occurs in the primary ignition circuit
A vehicle towed into the shop with a "cranks but doesn't start" problem. A quick check under the hood reveals that the spark plugs are not firing and the injectors are not receiving a pulse from the PCM. The technician notices that the MIL light does not come on when the key is turned to the run position. What would you do next? Select one: a. Check the PCM's fuses, power wires, and ground wires b. Replace the PCM c. Check the main power relay in the power distribution center d. Check for codes with a scan tool
Check the PCM's fuses, power wires, and ground wires
Which of the following is not a type of electronic ignition system? Select one: a. DI [distributor ignition] b. MAF [mass airflow] c. DLI [distributorless ignition] d. DI [direct ignition]
DI [distributor ignition]
A MAP sensor with a varying frequency output can be tested with a(n) ______. Select one: a. voltmeter b. ohmmeter c. DMM with a duty cycle function d. DMM with a frequency function
DMM with a frequency function
Which of the following is NOT an advantage of an electronic spark control system? Select one: a. It compensates for changes in engine (and sometimes outside air) temperature b. It allows lower compression ratio engines to be equally as efficient as higher compression ratio engines c. It makes changes many times faster than older (mechanical) systems d. It has a feedback mechanism in which sensor readings allow it to constantly compensate for changing conditions
It allows lower compression ratio engines to be equally as efficient as higher compression ratio engines
Which of the following is NOT an actuator? Select one: a. PCV valve b. fuel injector c. canister purge solenoid d. idle air control valve
PCV valve
Which statement is NOT true? Select one: a. Some sensors are voltage or frequency generators b. Some sensors are variable resistors c. Some sensors are simple on-off switches d. Some sensors are solenoids
Some sensors are solenoids
For most actuators, the circuit driver in the PCM applies a ground to the circuit to turn the actuator on and removes the ground to turn the actuator off.
True
If the MIL light is ON, there will be a DTC and associated freeze frame data stored in the PCM's memory.
True
Insufficient timing advance or retarded timing at higher engine speeds could cause hesitation and poor fuel economy.
True
Many of the inputs used for ignition system control are also used to control other systems,such as fuel injection
True
Mode 6 data are the results of the monitor diagnostic tests.
True
On some vehicles, actuators can be tested with a scan tool by accessing output state control (OSC) or output test mode (OTM). In this mode, the actuator enabled or disabled, or the duty cycle increased or decreased.
True
Port fuel injection systems have a throttle plate assembly, but fuel never passes by the plate.
True
The distributorless ignition system of a V-6 engine may be designed with three ignition coils.
True
The misfire monitor uses a high data rate CKP [crankshaft position] sensor to detect engine misfires, and the CMP [camshaft position] sensor is used to identify which cylinder is misfiring.
True
The waste-spark ignition system on a four cylinder engine with dual plug [two spark plugs per cylinder] cylinder heads requires four ignition coils.
True
A vehicle with a DTC for an engine coolant temperature out of range code is being tested.The serial data stream shows the coolant temperature to be 198 degrees Fahrenheit. When the technician tests the resistance between the ETC terminals, he finds infinite resistance. The specifications call for 20 to 40 ohms at 200 degrees Fahrenheit. After the ECT is replaced and the code is erased, the system runs normally and the code and MIL illumination do not reoccur. How is this possible? Select one: a. There was excessive air in the cooling system; when the ECT sensor was removed, the trapped air bled out b. The ETC code was set by a loose connection where the harness meets the ECT terminals; disconnecting and reconnecting the plug essentially fixed the problem c. The problem is an intermittent electrical fault; it will eventually reoccur d. When the ECT failed, the PCM substituted a nominal ECT value that allowed the engine to run in limp home mode; the substituted value was displayed by the scan tool
When the ECT failed, the PCM substituted a nominal ECT value that allowed the engine to run in limp home mode; the substituted value was displayed by the scan tool
A camshaft position sensor provides the PCM with data needed to control _____. Select one: a. fuel injector timing b. variable valve timing c. ignition coil timing (COP ignition) d. all answers are correct
all answers are correct
An air/fuel ratio sensor is different from an oxygen sensor in that ______. Select one: a. the signal output is a varying current (amps) b. as the mixture becomes leaner, its output signal increases c. the output responds to minor changes in air/fuel mixture, not just rich/lean conditions d. all answers are correct
all answers are correct
To minimize EMI interference, sensor wires should be routed away from _____. Select one: a. spark plug wires b. ignition coils c. distributor caps d. all answers are correct
all answers are correct
Which of the following tools cannot be used to test an oxygen sensor? Select one: a. digital voltmeter (DMM) b. analog voltmeter c. lab scope d. scan tool
analog voltmeter
Ignition spark typically occurs a few degrees _______. Select one: a. before top dead center [BTDC] b. after top dead center [ATDC] c. before bottom dead center [BBDC] d. after bottom dead center [ABDC]
before top dead center [BTDC]
Crankshaft position sensors [CKP] are _____ type sensors. Select one: a. Hall-effect b. magnetic pulse generators c. both "Hall-effect" and "magnetic pulse generators" d. neither "Hall-effect" nor "magnetic pulse generators"
both "Hall-effect" and "magnetic pulse generators"
What happens when the low-voltage current flow in the coil primary winding is interrupted by the switching device? Select one: a. The magnetic field around the primary winding collapses b. The movement of the magnetic field across the winding induces a high voltage in the secondary winding c. both "The magnetic field around the primary winding collapses" and "The movement of the magnetic field across the winding induces a high voltage in the secondary winding" d. neither "The magnetic field around the primary winding collapses" nor "The movement of the magnetic field across the winding induces a high voltage in the secondary winding
both "The magnetic field around the primary winding collapses" and "The movement of the magnetic field across the winding induces a high voltage in the secondary winding"
A no-start condition on an EI system is being discussed. Technician A says to use a test spark plug to determine whether the problem is in the ignition system. Technician B says that if a noid light is connected to the injector harness and it pulses while the engine is cranked, the triggering unit for the primary ignition circuit should be okay. Who is correct?
both A and B
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? Select one: a. A only b. B only c. both A and B d. neither A nor B
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? Select one: a. A only b. B only c. both A and B d. neither A nor B
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? Select one: a. A only b. B only c. both A and B d. neither A nor B
both A and B
Technician A says a fouled spark plug can cause a misfire. Technician B says a bad coil can cause a misfire. Who is correct?
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?
both A and B
Technician A says a magnetic pulse generator type sensor generates a small AC voltageeach time one of the machined slots in the trigger wheel passes by. Technician B says some ignition systems use dual Hall-effect sensors that produce a 3x and 18x/revolution pulse. Who is correct? Select one: a. A only b. B only c. both A and B d. neither A nor B
both A and B
Technician A says spark plugs are part of the secondary ignition circuit. Technician B says the battery is part of the primary ignition circuit. Who is correct? Select one: a. A only b. B only c. both A and B d. neither A nor B
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? Select one: a. A only b. B only c. both A and B d. neither A nor B
both A and B
Two technicians are discussing IAT sensors (intake air temperature). Technician A says the IAT sensor is an integral part of the mass airflow sensor (MAF). Technician B says the IAT is a discrete sensor located in the intake air passages or air cleaner assembly. Who is correct? Select one: a. A only b. B only c. both A and B d. neither A nor B
both A and B
While discussing electronic ignition systems, Technician A says an NPN transistor in the PCM or ignition module controls primary current flow through the coil. Technician B says coil saturation is controlled by the length of time the primary ignition current is turned on. Who is correct? Select one: a. A only b. B only c. both A and B d. neither A nor B
both A and B
All the following elements except _____ are used in the spark plug center electrode to increase plug life. Select one: a. platinum b. iridium c. yttrium d. cesium
cesium
The device that protects the PCM and other electronic components from the voltage spike created in the windings of a solenoid, relay, or magnetic clutch when they are turned off is called a ______. Select one: a. filter choke b. clamping diode c. suppression capacitor d. voltage divider
clamping diode
An accelerator pedal position sensor (APP) is used on vehicles equipped with ______. Select one: a. electronic throttle control b. cruise control c. torque converter clutch (TCC) d. all answers are correct
electronic throttle control
The first decision the computer makes in determining the best operating strategy is to determine the _____. Select one: a. throttle opening b. engine operating mode (cranking, idling, cruise, etc.) c. outside air temperature d. barometric pressure
engine operating mode (cranking, idling, cruise, etc.)
The sensor and output status data stored when a DTC is set is called ______. Select one: a. snap shot data b. freeze frame data c. mode 6 data d. failure record
freeze frame data
The engine coolant temperature sensor helps to control all the following EXCEPT: Select one: a. fuel pressure b. open loop/closed loop operation c. EGR opening d. ignition timing
fuel pressure
Which of the following is NOT a cause of spark knock? Select one: a. excessively advanced ignition timing b. engine overheating c. excessively lean air/fuel mixture d. high-octane fuel
high-octane fuel
Which of the following components is part of the primary and secondary ignition circuits? Select one: a. spark plugs b. ignition coil c. battery d. ignition switch
ignition coil
Which of the following tools should not be used to test an actuator unless the technician is directed to do so by the manufacturer's service procedures? Select one: a. scan tool b. DMM c. jumper wires d. lab scope
jumper wires
A technician connects a DMM with a MIN/MAX/AVG function to the output of an oxygen sensor. The engine is run at 2000 RPM for several minutes. During the test, the voltage toggles rapidly between 150 and 900 millivolts. At the end of the test, the MAX voltage was .967 V, the MIN voltage was .087 V, and the AVG voltage was .683 V. Technician A says the sensor is faulty and should be replaced. Technician B says there could be a vacuum leak that caused the sensor voltage to have a higher than normal average. Who is correct? Select one: a. A only b. B only c. both A and B d. neither A nor B
neither A nor B
Air/fuel ratios are being discussed. Technician A says that when the air fuel ratio is higher than 14.7 to 1 the engine produces more power. Technician B says that when the air fuel ratio is lower than 14.7 to 1 the engine uses less fuel. Who is correct? Select one: a. A only b. B only c. both A and B d. neither A nor B
neither A nor B
Spark plug wires are being discussed. Technician A says silicon-insulated wires are used for normal temperature applications. Technician B says hypalon-insulated wires are used for high-temperature applications. Who is correct? Select one: a. A only b. B only c. both A and B d. neither A nor B
neither A nor B
Which of the following is NOT the location of the ignition module? Select one: a. inside the distributor b. underneath the coil packs c. on the steering column, behind the ignition switch d. integral with the PCM
on the steering column, behind the ignition switch
Which of the following sensors is NOT used by the computerized ignition system to control ignition timing? Select one: a. oxygen sensor b. engine temperature c. manifold vacuum d. engine RPM
oxygen sensor
The magnetic field surrounding the pickup coil in a magnetic pulse generator moves when the ______. Select one: a. reluctor tooth approaches the ignition coil b. reluctor tooth begins to move away from the pickup coil c. reluctor tooth begins to move away from the ignition coil d. the pickup coil is midway between two reluctor teeth
reluctor tooth begins to move away from the pickup coil
One of the advantages of a coil-on-plug type ignition system is that it eliminates the need for ______. Select one: a. crankshaft position sensor [CKP] b. camshaft position sensor [CMP] c. knock sensor [KS] d. spark plug wires
spark plug wires
Which of the following tools is NOT used in testing engine sensors? Select one: a. DMM b. test light c. scan tool d. lab scope
test light
The injector pulse width is ______. Select one: a. the size of the injector nozzle b. the amount of time the injector opens and sprays fuel c. the voltage applied to the injector solenoid coil d. the distance between the injector tip and the center of the intake port
the amount of time the injector opens and sprays fuel
If the spark line is totally flat, is longer than 2 ms, and is less than 500 volts, there is a good chance that: Select one: a. the plug is not firing b. the air/fuel ratio is excessively lean c. there is high resistance in the spark plug wires d. the spark plug heat range is wrong for the engine
the plug is not firing
Which of the following is not a PCM output? Select one: a. solenoids b. thermostats c. lights (indicator) d. relays
thermostats
To read flash codes on an OBD I Chrysler-built vehicle ______. Select one: a. connect terminals A and B on the DLC with a jumper wire b. turn the rotary switch on the PCM counter clockwise 3 clicks c. connect the E1 and TE1 terminals on the DLC d. turn the ignition key on and off three times in five seconds, ending in on
turn the ignition key on and off three times in five seconds, ending in on
On an OBD-II vehicle, the DLC connector is located _____. Select one: a. under the hood, on the left side inner fender b. under the hood, on the right side inner fender c. under the hood, in the fuse/relay box d. under the dashboard, within arm's reach of the driver
under the dashboard, within arm's reach of the driver
