Electrical/Electronic Systems

Another way of saying 75 millivolts is: A. 0.075 volts B, 0.75 volts C. 7.5 volts D. 7.05 volts

A. 75 millivolts = 0.075 volts.

An air bag system is being serviced, Technician A says to disconnect the yellow SRS connectors at the front of the vehicle. Technician B says to disconnect and isolate the negative battery cable. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A or B

.B

Two lights are connected in parallel. An additional light is added, also wired in parallel. Technician A says the total resistance will decrease. Technician B says the total voltage will drop. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A or B

A. Adding an additional path through which the current can flow has decreased the total resistance of the circuit. Each light drops 12 volts.

A horn makes a very weak sound. Technician A says a faulty power connection could be the cause. Technician B says a faulty fuse could be the cause. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A or B

A. If horn sound is a weak tone, current is too low, and poor electrical connections may be the culprit, If a fuse is blown, the horn will not sound at all.

Which of these is best to use for testing networked components for proper operation when a vehicle is not actually being driven on the road? A. A jumper wire B. A bi-directional scan tool C. A digital volt-ohm meter D. A backprobe device

B. A bi-directional scan tool can be used to command on-board actuators to perform their duty when the vehicle is either in for service, or when it can be safely done while the vehicle is on the road.

Technician A says that all power should be removed from a circuit before testing the circuit with an ammeter. Technician B says that ail power should be removed from a circuit before testing the circuit with an ohmmeter. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A or B

B. When using an ohmmeter, all power should be removed from the circuit to be tested. Power to the circuit is necessary when testing a circuit with an ammeter.

All of the following could cause an inoperative starter EXCEPT: A. an improperly adjusted neutral safety switch B. worn or missing flywheel ring gear teeth C. an open circuit between the solenoid and the ignition switch D. an open in the solenoid ground circuit

B. Worn or missing fly-wheel ring gear teeth may not enable the starter to crank the engine, hut would not cause the starter itself to be inoperative. All of the other choices could prevent the starter from operating.

Technician A says that a battery with an open circuit voltage of 12.1 volts Is fully charged. Technician B says that if the Indlcator on a sealed maintenance-free battery Is yellow, the battery shouid be charged. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A or B

D. A battery with a 12.1 volt reading is undercharged. Technician B is wrong because if the indicator is yellow on a sealed maintenance-free battery, it means that the fluid level is below the level of the hydrometer. The battery should not be charged and should be replaced.

Technician A says that using a 20,000 ohm/volt analog meter ts a good choice for ECM clroult testing. Technician B says that oarefui use of a test light can determine the condition of a Throttle Position (TP) sensor. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A or B

D. An analog meter with a low input resistance should only be usedfor non-computer type circuits; a test light should never be used to diagnose sensor circuitry.

Technician A says that a digital ohmmeter should be manually set to "zero" after the switch is turned on. Technician B says that the resistance of a component should be checked while voltage is applied to the circuit. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A or B

D. Technician A is wrong because digital ohmmeters do not need to be zeroed before use. Test lead continuity should be checked however, by touching the two ohmmeter leads together and watching for a zero reading on the meter. Technician B is wrong because an ohmmeter is used to check the resistance of a component or wire while there is no voltage applied to the circuit. Current flow from an outside voltage source,such as the vehicle battery, can damage the ohmmeter, so the circuit or component should be isolated from the vehicle electrical system before any testing is done.

Technician A says that voltage in a series circuit should be the same at all loads of the circuit. Technician B says that current In a series circuit is the sum of all the components' current draw in a circuit. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A or B

D. Total voltage in a series circuit is equal to the sum of the voltages across the separate resistances. Total current in a series circuit is the same throughout left sides.

When using a voltmeter to check for voltage in a circuit, the voltmeter should first be connected to check for: A. source voltage. B. excessive resistance C. excessive amperage. D. a good ground.

.a

When troubleshooting a slow drain on the battery, which if these diagnostic tools should be used? A. Ohmmeter B. Ammeter C. Voltmeter D. Test fight

.b

A vehicle's tum signals flash too slowly. Technician A claims that the condition could be caused by a faulty flasher. Technician B says that a bulb may be the wrong type. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A or B

.c

Technician A says that checked with an ohmmeter, a diode should have a high resistance in one direction only. Technician B says a diode permits the flow of electricity in both directions. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A or B

A. A diode is a semiconductor that permits the flow of electricity in only one direction. When checking a diode with an ohmmeter, put the probes with red on the N-side; black goes on the P-side. Read the resistance, then reverse the leads. The diode should have a high resistance in one direction only.

What is meant by the term MUX? A. Multiphase switch B. Multiplexed network C. Micro-unitized assembly D. Magnetic unit-injector

B. MUX stands for "multiplex", which is the basis of operation for the type of communication system used in network equipped vehicles.

The oil pressure light on a vehlole dashboard stays on whenever the engine is running. The oil pressure has been checked with a mechanical gauge and it is within specifications. Technician A says that the circuit between the indicator light and the pressure switch could be grounded. Technician B says that an open in the pressure switch Itself could be the cause. Who Is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A or B

.a

Technician A says that a noisy alternator could be caused by a bad diode. Technician B says that a noisy alternator could be caused by a worn bearing. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A or B

.c

Both headlights on a vehicle are dim on high beam but are normal on low beam. Technician A says that a poor headlight ground could be the cause. Technician B says that a shorted headlight switch could be the cause. Who Is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A or B

.d

The analog ohmmeter needle does not move when connected as shown above. (pg 82) This indicates that the rotor winding is: A. shorted B. grounded C. complete D. open

.d

The fault shown in the above circuit is: (pg. 81) A. an open B. a short to ground C. too much capacitance D. too much resistance

B

A vehicle continues to trip the windshield wiper circuit breaker. Technician A says the cause could be a short circuit Technician B says that the cause could be binding wiper linkage. Who is right? A. Technician A only B. Teohnician B only C. Both A and B D. Neither A or B

C. A circuit breaker will disconnect the circuit if the circuit has higher than normal current flow, which can be caused by a short in the circuit or a binding of the wiper linkage.

When performing soldering, the purpose of a soldering iron is to heat the: A. flux. B. solder. C. conductors. D. heat shrink tubing.

C. Contrary to popular belief, the purpose of the soldering iron is not to melt the solder itself, but rather to heat the parts being soldered.

Technician A says a short circuit to ground in a circuit will decrease resistance. Technician B says a short circuit will Increase current flow. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A or B

.c

A communications failure in the CAN system will set what type of OTC? A. B - Body B. C - Chassis C. P - Powertrain D. U - Network

D. The onboard diagnostic system will set a code beginning with the letter U.

While testing a starting circuit on a 5.7L V8 engine, the technician finds that the engine cranks slowly. The starter current draw is 90 amps, and the battery voltage while cranking is 11 volts. What should the technician do next? A. Check for voltage drop of the starter motor circuit. B. Test the battery capacity. C. Replace the starter motor, as a short Is indicated. D. Determine the condition of the engine.

.a

The condition of a lead-acid battery is being checked. Technician A says to use a galvanometer. Technician B says to use a capacitive battery tester. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A or B

.b

When checking the green eye of a sealed maintenance-free battery, no color seen indicates that the battery is: A. undercharged. B. charged properly. C. overcharged. D. damaged.

.a

Which of these should be used when soldering electrician wiring connections? A. rosin core flux B. acid core flux C. sulfur core flux D. none of the above

.a

The doors will not unlock on a vehicle using the remote keyless entry. Any of these could be the cause EXCEPT: A. a weak transmitter battery B. interference from a stronger radio transmitter C. a bad passenger's door lock motor D. a blown circuit breaker

C. A faulty passenger's door lock motor would only affect that door and would not prevent other doors from opening with the remote keyless entry. All of the other choices could prevent all the doors from opening using keyless entry.

The wiring diagram symbol shown represents a: (pg 89) A. fuse B. circuit breaker C. relay D. switch

C. The symbol shown represents a relay.

Nothing happens when the ignition key Is turned to the START posltion In a vehicle with a good battery. Teohnician A says that If a clicking sound is heard when a jumper wire is 'connected between the battery and the solenoid 'S' terminal, a problem exists in the starter control circuit. Technician B says that if a jumper wire is connected between the battery and the soienold 'S' terminal and there Is no sound, the starter Is defective. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A or B

D. If a jumper wire is connected between the battery and the solenoid 'S' terminal and the engine cranks, there is a problem in the starter control circuit. If the solenoid makes a clicking sound, it Is operating properly and the problem may be with the starter. If no sound is heard, the solenoid is defective and should be replaced.

Which of these is most useful for first diagnosing vehicles with multiplex (networked) electrical systems? A. A voltmeter B. An oscilloscope C. A logic probe D. A scan tool

D. Multiplexed networks can be monitored and tested using an OEM or equivalent scan tool.

The voltmeter meter in the circuit shown above reads 3.5 volts. (pg 82) Technician A says that a bad ground for the light could be the cause. Technician B says that high resistance in the circuit from the battery to the light could be the cause. Who is right?? A. Technician A only B. Technician B only C. Both A and B D. Neither A or B

.b

When testing computer-controlled systems, a digital multimeter should be used with an input impedance of at least: A. lOk ohms B. lOOk ohms C. 1 megohm D. 10 megohms

.d

Which of these would be the MOST useful for diagnosing an intermittent electrical problem? A. oscilloscope B. digital voltmeter C. analog voltmeter D. logic probe

A. An oscilloscope is especially useful for diagnosing intermittent problems that might not be detected with a voltmeter. An analog voltmeter only displays average values and a digital voltmeter samples voltage several times each second, but because an oscilloscope displays actual voltage it will show any momentary changes in the signal. These momentary changes can be caused by an intermittent open in the circuit or an intermittent short to power or ground. A test light does not indicate that 12 volts (or any particular amount of voltage) are present; it only indicates that some voltage is present.

The horns in the circuit shown above (pg 84) only blow when a jumper wire is connected between terminals 1 and 2 of the horn relay. Technician A says that a bad horn relay could be the cause. Technician B says that a ground in the circuit between the horn relay and the horn button could be the cause. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A or B

A. Connecting a jumper wire between terminals 1 and 2 would bypass the relay and supply direct voltage from the battery to the horns, indicating a possible bad horn relay. If the circuit between the horn button and the horn relay were grounded, the horn relay would be energized and the horns would blow all the time.

A rear defogger grid is being tested. Technician A says that when probing a grid line, the voltmeter should decrease its reading as the probe gets closer to the ground bus bar. Technician B says that if voltmeter read 12 volts at both ends of the grid line, there is an open in the grid line. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A or B

A. If the test light remains bright at both ends of the grid lines, check for a loose ground. If there is an open in a grid line, the test light will not get dimmer and will stay the same brilliance until it reaches the other side of the open, at which point it will go out.

When checking exterior LED fights on a vehicle, all of these can be checked EXCEPT: A. condition of filament. B. continuity C. power circuit D. ground circuit

A. LED lights have no filament, so a visual inspection will not determine whether the light is good, If an LED light assembly does not illuminate, check the light for an open circuit, inspect the wiring and make sure there is power to the light, just as you would for a conventional incandescent light.

All of these are used when applying Ohm's Law EXCEPT: A. amperes (i) B. watts (W) C. ohms CR) D. voltage CE)

B. The components of Ohm's Law include voltage (E), amperes (I) and ohms (R). t

In the schematic shown above (pg 91), only the console and the radio are illuminated when the lights are turned on. Which of these could be the cause? A. A blown five amp fuse B. A faulty connection at C216 C. A loose connection at G1002 D. A faulty connection at C504

C. A blown fuse or a faulty connection at C216 would prevent all the lights from working. A poor connection at C504 would prevent the radio light from working and we know from the question that it works. The radio is case grounded and the console light also has a separate ground. However, all the other lights share the G1002 ground and a poor connection there could cause an open circuit and keep those lights from working.

The charging system on a vehicle undercharges. Technician A says the cause could be a loose alternator drive belt. Technician B says the cause could be a defective ECM. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A or B

C. A loose alternator drive belt could cause reduced charging system output voltage, but on some vehicles, so could a defective ECM. The PCM/ECM regulates alternator output voltage on many newer vehicles, The PCM/ECM either supplies power or ground to the alternator field, depending on the system. The power or ground is pulse-width modulated in response to the amount of sensing voltage.

The sunroof on a vehicle works intermittently. Technician A says there could be a poor wiring connection. Technician B says the panel could be binding in the rails. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A or B

C. Loose or corroded connections could cause an intermittent problem. The glass binding in the rails could cause the electric motor to overheat and trip the circuit breaker. After the breaker cools and resets, the panel may work again until the binding again trips the breaker.

A customer complains of static on the radio. Technician A says that loose or missing ground wires could be the cause. Technician B says that a defective antenna cable could be the cause. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A or B

C. Poor sound quality, static and poor reception can be caused by a defective antenna, an antenna that is not grounded or connected properly or one that is not trimmed properly. Static can also be caused by faulty ignition components, loose or missing ground wires and defective noise suppression devices.

All of the following are indications of an under-charged battery condition EXCEPT: A. slow cranking B. dim headlights C. short light bulb fife D. low ammeter indication

C. Short light bulb life and a battery that continually needs water ar indications of over charging.

A power seat system is extremely noisy when operated. All of the following could be the cause EXCEPT a: A. faulty motor B. faulty transmission C. bad ground D. lack of lubricant

C. While a bad ground would disable the system or make the power seat operate slowly, it would not be the cause of noisy operation.

The next question refer to the interval windshield wiper/washer wiring schematic shown above. (pg 90) The wipers only work on high speed. All of the following could be the cause EXCEPT: A. a defective wiper switch B. a loose connection at G1002 C. a defective interval governor D. an open in the DB/O wire

D. An open in the DB/O wire would prevent high-speed operation and the question states that the wipers only work on high. A bad governor ground could prevent low and interval operation so a loose connection at G1002 could be the cause. No voltage ac terminals L and I of the main switch could mean that the switch is faulty. However, if there is voltage at terntinals L and I and wires 65 and 993 are OK, the governor should be replaced.

The left power window in the illustration above (pg 86) operates in the UP position, but not in the DOWN position. The right power window operates in both UP and DOWN positions. Technician A says that the BRN wire is open. Technician B says that the DK BLU wire is open. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A or B

D. If the BRN wire is open, the left window would not have a return or ground wire in the UP position and would not have a supply or voltage wire in the DOWN position. If the DRK BLU wire is open, the left window would not have a return or ground wire in the DOWN position and would not have a supply or voltage wire in the UP position. A possible bad switch LH WINDOW UP contact in the Master Switch Assembly would cause the problem.

In the test shown above (pg 89), the voltmeter reads 0.3volts. Technician A says this indicates there is excessive resistance in the starter power circuit. Technician B says this indicates there is excessive resistance in the starter ground circuit. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A or B

D. Technician A is wrong because 0.3 volts is within specification for voltage drop in a starter power circuit. Technician B is wrong because the starter ground circuit is not being tested in the illustration.

What is the best course of action to be taken if a heated seat grid is found to be faulty? A. Send the seat to the dealer for needed electrical repairs. B. Take the seat apart and repair the defective heater grid. C. Replace the complete seat assembly with a new one. D. Send the seat to an automotive upholstery shop for repair.

D. The best course of action, unless a qualified upholstery technician is on staff, is to send the seat out for repair at an automotive upholstery shop. The special tools needed and the labor time involved would otherwise be prohibitive.

The front and rear turn signals on the left side of a vehicle are non-functional. Technician A says the turn signal flasher could be shorted to ground. Technician B says the hazard flasher could be shorted to ground. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A or B

D. The flasher or fuses would affect both right and left sides. The most likely cause is two bad bulbs, a defective turn signal switch or a problem in the wiring that is common to the front and rear on the left side of the vehicle.

Technician A says that an in-vehicle high-rate discharge battery load test shouid always be performed if a 12-volt battery if its condition is in questlon. Technician B says that the battery should be discharged (loaded) at twice its ampere hour rating. Who Is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A or B

D. The high-rate discharge (load) test of a battery. Is frowned upon by OEMs because of the likely hood of over stressing the alternator. If done with the battery removed (or disconnected) from the vehicle, the load applied should be three times the battery's ampere-hour rating or half of its CCA rating.

All of these types of headlights are found on today's vehicle's EXCEPT for: A. conventional sealed beams headlamps. B. composite sealed beams headlamps. C. Xenon headlamps. D. LED headlamps.

A. Conventional sealed beams have all but been replaced by the other types of headlamps listed in this question

The next question refer to the interval windshield wiper/washer wiring schematic shown above. (pg 90) The wipers do not work in the interval position. Which of the following should the technician do first? A. Measure resistance at terminals Rl and R2. B. Replace the interval governor. C. Check the fuse. D. Check for an open circuit at S303.

A. If the fuse were bad, the wipers would not work at all, and the question states that they only don't work in the interval position. An open at S303 would affect the washer pump but not the wipers. The interval governor should not be condemned until the resistance is checked at terminals RI and R2 of the wiper switch. If the resistance doesn't vary when the interval adjustment is turned, the wiper switch should be replaced. If the interval adjustment varies the resiscance, the interval governor should be replaced.

Technician A says that a test tight is a good diagnostic tool for testing solid-state electronic circuits. Technician B says that an ohmmeter is a good diagnostic tool for testing voltage sources. Who is right? A. Technician A only B. Technlcian B only C. Both A and B D. Neither A or B

D. A test light may overload electrical circuits that contain solid-state components. Because an ohmmeter has its own battery, any circuit being tested should be disconnected from its voltage source.

The backup lights in the circuit shown above right do not work. (pg 88) Which of these is the MOST LIKELY cause? A. a corroded connector C402 B. a break in the black wire between connector C400 and splice S404 C. both backup light bulbs are burned out D. the backup light switch is faulty

D. Answers A and B are wrong because either problem would only affect one light and the question states that both lights do not work. Answer C is possible but it is not probable that both bulbs burned out at the same time. A faulty switch would affect both backup lights and is the most likely cause for failure of the choices given.

All of the following warning system lights use a grounding switch EXCEPT: A. oil pressure B. coolant temperature C. brake warning D. charging system

D. Charging system warning lights are controlled by charging voltage. The light bulb is not grounded at the instrument panel. Instead, current flows through the bulb and eventually grounds at the ground brush inside the alternator. When the alternator is charging, current flows through a wire to the opposite side of the bulb from the ignition switch. Because both sides of the bulb receive similar voltages, no current flows through the bulb and it doesn't light.

The Interior lights in a vehicle stay on all the time. Technician A says that a door switch could be stuck. Technician B says there could be a short to ground in the circuit before one of the switches. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A or B

B. A door switch is a grounding switch that completes the courtesy light circuit when a door is opened. When the door is closed, the switch opens and the interior lights go out. It is more likely that a door switch would stick in the open position, so Technician A is wrong. Technician B is right because a short to ground in the circuit before the door switch would complete the circuit, making the lights stay on regardless of switch position.

Which of the parts schematically shown above (pg 88) is sometimes used in a headlight switch? A. fixed type B. variable rheostat type C. variable potentiometer type D. thermistor

B. A rheostat is a type of variable resistor that has two terminals. One terminal is connected to the fixed end of the resistor and the other is connected to a movable contact called a wiper. The resistance Is varied by moving the position of the wiper on the resistor, thereby increasing or decreasing the electrical current. In a headlight switch, the knob is connected to the wiper and as the knob is turned, the instrument panel lights dim or brighten. The other type of variable resistor, the potentiometer, is a three-terminal resistor. Potentiometers are communal used in electronic engine control system sensors, such as the Throttle Position (TP) sensor.

All of the gauges on a vehicle work except the coolant temperature gauge. A variable resistor is connected between the sending unit wire and ground. With the Ignition switch ON the resistance is varied, making the gauge needle move. Technician A says the instrument voltage regulator could be the cause. Technician B says the sending unit could be faulty. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A or B

B. If all the gauges were dead, then the cause would probably be the instrument voltage regulator. However, only the temperature gauge is inoperative. The gauge was tested properly in the question so a faulty sending unit is indicated. The resistance of the sending unit can be checked by connecting an ohmmeter between the terminal lead and ground. The resistance value should change in proportion to the coolant temperature. Compare results with the manufacturer's specifications.

The brake light on the right side of a vehicle is dim compared with the one on the left. A technician tests the circuit with a voltmeter. With the brake pedal applied, the voltmeter negative lead connected to the negative battery terminal and the positive lead connected to the light socket, the voltmeter reading is 6.2volts. What does the voltmeter reading indicate? A. an open ground circuit B. high resistance in the ground circuit C. low resistance in the ground circuit D. a bad light bulb

B. If there were an open ground circuit or the bulb was bad, the light would not work at all. Since the bulb is working, but not optimally, the technician is voltage drop testing. If the circuit was operating properly, the voltmeter reading would be 0.0 volts and no higher than 0.5 volts. This would mean that all the system voltage was being used by the light. The reading of 6.2 volts means that there is excessive resistance in the circuit, robbing the light of the necessary voltage needed for optimal illumination. The technician should continue checking the ground path until the voltmeter reading returns to normal and repair the problem connection.

Technician A says that a self-resetting circuit breaker is sometimes used in a taillight circuit. Technician B says that the colored insulation of a fusible link indicates the amount of circuit protection available. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A or B

B. Resetting circuit breakers are not used in taillight circuits. Fusible links arc often identified by colored insulation-red, pink, brown, yellow, etc. The color indicates the amount of maximum circuit protection available.

Technician A says that if the washer pump ground circuit (as shown above, pg 87) is faulty, the wiper motor will not run. Technician B says that the wiper motor shown will continue to run after the switch is opened until the park switch also opens. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A or B

B. Tech A states that a bad washer motor ground will prevent the wiper motor from working. This is wrong. The washer motor ground serves as a ground for the washer motor and would not affect the action of the wiper motor. Tech B explains the wiper motor park circuit shown in the illustration. The wiper motor will continue to run after the switch is opened until the cam opens the park switch.

Neither of the low beam headlights on a vehicle will light but the high beams work normally. Technician A says the headlight thermal breaker could be faulty..Technician B says the dimmer switch may be faulty. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A or B

B. The headlight switch and breaker would also affect the high beams. The dimmer switch would affect both low beam headlights.

Technician A says that the rectifier bridge consisting of six diodes changes DC to AC voltage. Technician B says that an externally grounded alternator can be full-fielded by grounding the field terminal. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A or B

B. The rectifier bridge changes AC voltage to DC voltage. To test an externally grounded alternator, make sure all lights and accessories are off. Set the engine rpm to 1500-2000 rpm. Now ground the field according to the manufacturer's recommended procedure. Full amperage output should be indicated if the alternator is in good condition and being driven properly.

A start/clutch interlock switch is being tested. Technician A says that, with the clutch pedal in the released position, the switch should have continuity when checked with an ohmmeter. Technician B says that, with the pedal depressed, there should be voltage on both sides of the switch when checked with a voltmeter. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A or B

B. The start/clutch interlock switch is open when the dutch pedal is in the released position, interrupting current flow in the starter circuit. Technician A is wrong because an open switch should have no continuity. When the clutch pedal is depressed, the switch closes, allowing current flow in the circuit.

When checking a vehicle for DTCs, code U1064 is found: Loss of Communication with BCM. Technician A says that the BCM should be replaced. Technician B says the cause for the OTC could be another module in the network. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A or B

B. This code does not necessarily mean that the module has failed, but rather that there is a problem preventing communication. A communications DTC can be caused by a faulty connector or wiring, an open or short circuit, a voltage problem on the network, another module in the network, or the module itself.

When performing a current draw test using an ammeter, a reading greater than that which was specified would indicate: A. excessive circuit resistance B. a decrease in olrcult resistance C. an open circuit D. a decrease in circuit voltage

B. When performing a current draw test using an ammeter, a decrease in circuit resistance will cause a reading greater than what was specified.

The fuse for a power window system is blown. Any of these could be the cause EXCEPT: A. wire is shorted to ground somewhere in the circuit. B. the window track is binding. C. an open lexists in the motor's circuit. D. there is a short in the motor.

C. A fuse normally blows because of high current draw. A typical cause for a blown fuse is a short circuit. A short may occur in the wiring or motor itself. If a window is binding in its track, the motor will tend to draw an excessive amount of current. This high current draw may cause the circuit breaker to trip or a fuse to blow. The problem may also cause motor damage. An open circuit will draw zero current and therefore, would not be a cause for the blown fuse.

All of these are true statements regarding air bag supplemental restraint systems (SRS) EXCEPT: A. While removed from the vehicle, the airbag module should be stored with the cover pad facing up. B, Safety glasses should be worn when servicing the air bag system. C. Only rosin core solder and heat shrink tubing should be used to repair air bag system wiring. D. Performing tests Improperly or using the wrong equipment can result In accidental air bag deployment.

C. Air bag system wiring harnesses should not be repaired and only replaced. All of the other answers are true statements regarding air bag systems.

An ohmmeter is being used to check a circuit for continuity. Technician A says an infinity or full scale reading on an ohmmeter indicates no continuity. Technician B says a zero reading on an ohmmeter indicates continuity. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A or B

C. An infinity reading indicates an open wire; a zero or low reading indicates a good connection.

A circuit is wired in series. Technician A says the total of all voltage drops will equal the battery voltage. Technician B says the current flow through each part of the circuit Is the same. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A or B

C. Current remains constant throughout a circuit, and the total of all voltage drops always equals the source voltage provided.

A circuit is wired in parallel. Technician A says that total circuit current is divided across each load. Technician B says the voltage is the same at each load. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A or B

C. Current will be divided across the loads and the voltage is the same at each load.

In the charging system shown above, the reading will show: (pg 84) A. charging output voltage B. indicator lamp operating voltage C. charging circuit voltage drop D. ignition switch voltage

C. In the circuit shown in the illustration, the meter will show the charging circuit voltage drop from the alternator BAT terminal to the wire terminal or bus, to the positive battery post.

An electronic digital speedometer is stuck at zero. Technician A says that this could set a OTC. Technician B says that the Vehicle Speed Sensor (VSS) could be the problem. Who is right? A. Technician A only B. Technician B only C. Both A and B D. Neither A or B

C. The Body Control Module (BCM) in some systems can make diagnostic checks of the electronic instrument duster. The BCM monitors certain functions and will store a DTC if any are found to be outside of preprogrammed parameters. If the instrument duster passes a self-diagnostic test but the speedometer still remains at a certain speed or operates erratically, the problem is most likely in the VSS circuit.