Automotive Electrical Diagnostics AUT. 149 exam reiew

Sulfation can cause _____. battery freezing in subzero weather poor cranking in cold weather both "battery freezing in subzero weather" and "poor cranking in cold weather" neither "battery freezing in subzero weather" nor "poor cranking in cold weather"

"battery freezing in subzero weather" and "poor cranking in cold weather"

A cold-cranking amperes (CCA) rating specifies the minimum amperes available at _____ degrees Fahrenheit. 50 32 0 50

0

While conducting a battery drain test, if the ammeter reads _____ or more amperes, there is excessive drain. 0.100 0.050 0.250 2.500

0.250s

A technician is checking a circuit with excessive resistance. The current flow through the circuit should be 10 amps, but a check with an ammeter measures only 6 amps. The technician measures a voltage drop of 1.0 volts across the switch terminals when the circuit is turned on. What is the resistance of the switch? 1/16 ohm 1/6 ohm 6 ohms 60 ohms

1/6 ohm

How many volts are present in a fully charged 12-volt battery? 12.0 12.2 12.4 12.6

12.6

When setting up a lab scope to measure a waveform that ranges from 0 to 15 volts; if there are eight vertical divisions, what must the voltage level be set at to display the entire waveform? 100 millivolts 500 millivolts 1 volt 2 volts

2V

The electrolyte in a fully charged lead acid type battery is a solution of _____. 36 percent sulfuric acid and 64 percent water 40 percent hydrochloric acid and 60 percent water 30 percent potassium hydroxide and 70 percent water 50 percent hydrogen peroxide and 50 percent water

36 percent sulfuric acid and 64 percent water

A conductance tester measures the battery condition by _____. sending a small AC signal through the battery and measuring the current response applying a load of 125 amps on the battery and measuring how fast the battery voltage returns to 12.4 volts when the load is turned off measuring how fast the voltage drops when a 100 amp load is applied measuring the voltage drop between cells as a load is applied

: sending a small AC signal through the battery and measuring the current response

Technician A says jump-starting a battery can damage electronic components. Technician B says a dead battery should be jump-started instead of recharged. Who is correct? A only B only both A and B neither A nor B

A

A technician is testing a circuit that uses a ground-controlled relay to provide power to the circuit load. With the relay installed in its socket, the control terminal of the relay is grounded by a jumper wire; nothing happens. Technician A says check the coil input terminal for voltage. Technician B says connect a jumper wire between battery negative and the output terminal of the relay to check if the load is the problem. Who is correct? A only B only both A and B neither A nor B

A only

Resistance checks are being discussed. Technician A says the component must be disconnected from the system before checking. Technician B says an infinite reading means the component is shorted. Who is correct? A only B only both A and B neither A nor B

A only

Sensor problems are being discussed. Technician A says a poor ground in the reference voltage circuit can cause higher than normal readings at the computer. Technician B says small amounts of unwanted resistance in a low voltage sensor circuit will not have a significant effect on the vehicle's performance. Who is correct? A only B only both A and B neither A nor B

A only

Technician A says a battery strap or carrier should be used whenever a battery is lifted. Technician B says when a battery is removed, the positive cable should be disconnected first. Who is correct? A only B only both A and B neither A nor B

A only

Technician A says dielectric grease is used on wire terminals and connectors to prevent corrosion. Technician B says dielectric grease reduces the resistance between the terminals. Who is correct? A only B only both A and B neither A nor B

A only

Technician A says electrical circuit resistance causes voltage drop. Technician B says high-resistance problems cause an increase in current flow. Who is correct? A only B only both A and B neither A nor B

A only

Technician A says electrolyte is very corrosive. Technician B says electrolyte is a water and hydrochloric acid solution. Who is correct? A only B only both A and B neither A nor B

A only

Technician A uses a solution of baking soda and water to clean a battery. Technician B uses soap and water. Who is correct? A only B only both A and B neither A nor B

A only

Technician A uses the electrical schematic diagram to trace the flow of current through all the switches, wires, connectors, circuit protection devices, and grounds related to the problem before he begins testing. Technician B uses the schematic diagram to locate exactly where on the vehicle all of the circuit components are located. Who is correct? A only B only both A and B neither A nor B

A only

Corrosion on or near the battery must be minimized because _____. corrosion on the battery terminals increases resistance in the battery circuit corrosion on the battery cover can create a path that will allow the battery to slowly discharge corrosion can destroy the hold-down straps and battery tray all answers are correct

All

When depowering the high-voltage battery system of a hybrid vehicle, _____. lineman's gloves should be worn never wear anything metallic [jewelry] wait at least five minutes after disconnecting the HV batteries before working on the vehicle electrical system all answers are correct

All

When connecting a conventional ammeter to a circuit, _____. the circuit must turned on the ammeter must be wired in series with the circuit the anticipated load current must be less than the ammeter's maximum current rating all answers are correct

All are correct

All the following are lab scope adjustments EXCEPT: trigger level slope trigger source amperage level

Amperage level

Technician A fast charges a sulfated battery then reinstalls it in the vehicle. Technician B trickle charges a sulfated battery over 24 hours before reinstalling it. Who is correct? A only B only both A and B neither A nor B

B only

Technician A says the specific gravity of pure water is 10.00 at 80 degrees Fahrenheit (27 degrees Celsius). Technician B says the specific gravity of electrolyte in a fully charged battery is between 1.260 and 1.280 at 80 degrees Fahrenheit (27 degrees Celsius). Who is correct? A only B only both A and B neither A nor B

B only

When charging a battery that has been completely discharged, the most important item to monitor is _____. gassing charging voltage charging current battery temperature

Battery temp

Battery ratings are being discussed. Technician A says the reserve capacity rating is a measure of the battery's ability to operate the lights and electrical system in the event of a generator failure. Technician B says the cold-cranking amps rating is a measure of the battery's ability to provide current for the starter. Who is correct? A only B only both A and B neither A nor B

Both

Technician A says a circuit breaker can be reset after the problem that tripped the circuit breaker is fixed by disconnecting the power to the circuit breaker for a few seconds. Technician B says the circuit breaker can be reset by pressing the reset button on the breaker. Who is correct? A only B only both A and B neither A nor B

Both

Technician A says a positive battery plate consists of a grid filled with lead peroxide (Pb02). Technician B says lead peroxide is a porous, brown, crystalline material. Who is correct? A only B only both A and B neither A nor B

Both

Technician A says absorbed glass mat [AGM] batteries have spiral wound plates and never require water. Technician B says recombinant batteries use a gel-type electrolyte and convert oxygen and hydrogen back into water. Who is correct? A only B only both A and B neither A nor B

Both

Technician A says baking soda can be used to neutralize battery corrosion. Technician B says baking soda should be used to clean batteries. Who is correct? A only B only both A and B neither A nor B

Both

Technician A says lead in the lead peroxide of the positive plates combines with sulfate to form lead sulfate (PbSO4) as a battery discharges. Technician B says lead sulfate forms on the negative plates as a battery discharges. Who is correct? A only B only both A and B neither A nor B

Both

Technician A says overcharging can overheat and damage the battery. Technician B says overcharging causes gassing that can cause the battery to lose water. Who is correct? A only B only both A and B neither A nor B

Both

Technician A says uses an ohmmeter to measure resistance of a component. Technician B uses a voltmeter to measure voltage drop. Who is correct? A only B only both A and B neither A nor B

Both

Technician A uses a splice clip while soldering two wires together. Technician B twists the wire strands of the wire ends together before soldering. Who is correct? A only B only both A and B neither A nor B

Both

Technician A uses a voltmeter to test the open circuit voltage of a battery. Technician B uses the results of an open circuit voltage test to determine the battery's state of charge. Who is correct? A only B only both A and B neither A nor B

Both

Which method of testing for battery state of charge (SOC) can be used on maintenance-free batteries? built-in hydrometer open circuit voltage test battery hydrometer both "built-in hydrometer" and "open circuit voltage test"

Both

While discussing how to test a switch, Technician A says the action of the switch can be monitored by a voltmeter. Technician B says the continuity through the switch can be checked by measuring the resistance across the switch terminals using an ohmmeter. Who is correct? A only B only both A and B neither A nor B

Both

Voltage drop testing is being discussed. Technician A connects the red voltmeter lead to the most positive side of the circuit being tested and the black lead to the most negative side or part of the circuit being tested. Technician B says the test must be conducted with the circuit operating with normal amounts of current. Who is correct? A only B only both A and B neither A nor B

Both A and B

When testing the high-voltage circuits on a hybrid vehicle, a _____type meter and test leads must be used. Cat II Cat III Cat IV Cat V

Cat III

All the following information about the vehicle's wiring can be found in the electrical schematics with the exception of _____. wire color wire size connector terminal designation component location on vehicle

Component Location

Which of the following is NOT a common cause for premature battery failure? increased cycling sulfation excessive engine restarting overcharging

Excessive Engine Restarting

Battery charging should be done in a well-ventilated area because the gases produced during recharging are _____. highly toxic [poisonous] explosive both "highly toxic [poisonous]" and "explosive" neither "highly toxic [poisonous]" nor "explosive"

Explosive

The wave form of constant DC voltage on a lab scope is a _____. square wave sawtooth wave sine wave flat line

Flat Line

What is the first step when removing an old battery? Disconnect the positive cable Remove the battery hold-down straps and cover Inspect and clean the area Remove the heat shield

Inspect or clean the area

Oscilloscopes are being discussed. Technician A says the vertical positions represent time. Technician B says the horizontal positions represent voltage. Who is correct? A only B only both A and B neither A nor B

Neither

Technician A says fuses and other circuit protection devices normally wear out. Technician B says to avoid future problems, replace a bad fuse with a higher ampere-rated fuse. Who is correct? A only B only both A and B neither A nor B

Neither

Technician A says the reserve capacity rating of a battery is the amount of steady current that a fully charged battery can supply for 20 hours without the voltage dropping below 10.5 volts. Technician B says an ampere-hour rating states how many hours the battery is capable of supplying 25 amperes. Who is correct? A only B only both A and B neither A nor B

Neither

Technician A says when a battery is charging, it changes chemical energy into electrical energy. Technician B says when a battery is being discharged, it changes electrical energy into chemical energy. Who is correct? A only B only both A and B neither A nor B

Neither

Technician A says when battery cells are connected together in series, the amperage increases. Technician B says when battery cells are connected together in parallel, the voltage increases. Who is correct? A only B only both A and B neither A nor B

Neither

All the following are good safety precautions to follow when charging batteries EXCEPT: Always wear safety glasses Make sure the area is well ventilated Never charge a frozen battery or one with damaged plates Never allow the charging voltage to exceed 12.6 volts

Never allow the charging voltage to exceed 12.6 volts

The two types of battery cell designs used in high-voltage hybrid battery systems are cylindrical and _____. prismatic radial hyperbolic parabolic

Prismatic

A technician is diagnosing the cause of an insufficient heat problem. He notices the fan is working but not providing much air flow. He disconnects the fan power feed wire and connects the fan to the battery using a fused jumper wire. The specification for the fan motor is 16 amps. His ammeter shows 26 amps when the fan is jumped directly to the battery. What could be the problem? bad fan motor ground high resistance in the fan motor wiring shorted wiring in the fan motor all answers are correct

Shorted Wiring in fan motor

The waveform of AC voltage is typically a _____. square wave sawtooth wave sine wave flat line

Sine Wave

Which of the following components is not part of a battery cell? positive electrode negative electrode electrolyte solenoid

Solenoid

A potentiometer [type of variable resistor] can be tested with all the following tools EXCEPT: Test light Voltmeter Ohmmeter digital lab scope

Test Light

Which of these statements is NOT a true conclusion from a battery load test? The battery needs to be replaced if the voltage dropped below 9.6 volts while under a load but rose above 12.4 volts when the load was removed The battery should be charged and then retested because it dropped below 9.6 volts and didn't rise above 12.4 volts when the load was removed The battery should be charged and then retested because it dropped below 9.6 volts and rose above 12.4 volts when the load was removed The battery is good because the voltage dropped only to 10.3 volts while under load

The battery should be charged and then retested because it dropped below 9.6 volts and rose above 12.4 volts when the load was removed

DMMs that can measure temperature use a _____ adapter that is placed on or near the object to be checked. thermometer thermocouple manometer refractometer

Thermocouple

The radiator fan on a vehicle is working, but it is turning at a much slower speed than normal. The specifications for the fan motor are 25 amperes. Your DMM has a maximum amperage of 10 amps. What should you use to test the fan motor current? Replace the 10 amp fuse in your DMM with a 25 amp fuse Use an inductive type ammeter Both "Replace the 10 amp fuse in your DMM with a 25 amp fuse" and "Use an inductive type ammeter" Neither "Replace the 10 amp fuse in your DMM with a 25 amp fuse" nor "Use an inductive type ammeter"

Use an inductive type ammeter

The best way to test battery cables and terminal for excessive resistance is by _____ testing. ohmmeter voltage drop ammeter [conventional] inductive ammeter

Volt drop

The best method for testing wires and electrical connections is _____. ohmmeter test voltage drop test inductive ammeter infrared pyrometer

Voltage Drop Test

Technician A says jump-starting can cause a battery to explode. Technician B says jump-starting can damage a computer. Who is correct? A only B only both A and B neither A nor B

both

Technician A uses a voltmeter to check circuit resistance. Technician B uses an ohmmeter to check circuit resistance. Who is correct? A only B only both A and B neither A nor B

both

Technician A uses heat shrink tubing to insulate and seal soldered wire connections. Technician B wraps the soldered connection with electrical tape. Who is correct? A only B only both A and B neither A nor B

both

Battery overcharging may be caused by _____. faulty vehicle charging system improper use of a battery charger both "faulty vehicle charging system" and "improper use of a battery charger" neither both "faulty vehicle charging system" nor "improper use of a battery charger"

both "faulty vehicle charging system" and "improper use of a battery charger"

What is the best tool to use to find the cause of an intermittent problem in a low-voltage DC circuit? graphing multimeter [GMM] digital storage oscilloscope digital voltmeter test light

digital storage oscilloscope

A technician is testing a connector in a circuit with a voltmeter. With the power on in the circuit, the meter reads 12 volts when the leads are placed on each side of the connector. This indicates that the connector _____. is shorted to ground is open is good has current flowing through it

is open

Sulfation of battery plates can cause _____. lower specific gravity reduced reserve power in cold weather both "lower specific gravity" and "reduced reserve power in cold weather" neither both "lower specific gravity" nor "reduced reserve power in cold weather"

lower specific gravity" and "reduced reserve power in cold weather

When load testing a battery, the load applied to the battery should be _____. one half the CCA rating the CCA rating two times the CCA rating two times the CA rating

one half of the CCA rating

In a VRLA [valve regulated lead acid] recombinant type battery, _____. the gases produced in the recharging process are vented to the atmosphere the electrolyte is 100 percent water oxygen and hydrogen released during charging are converted back into water all answers are correct

oxygen and hydrogen released during charging are converted back into water

Which of the following is NOT part of routine battery inspections and maintenance? Visually check cables and terminals Make sure the battery hold-downs are holding the battery securely in place Refill the electrolyte level with clean electrolyte Clean any corrosion from the cable ends and terminals

refill the electrolyte level with clean electrolyte

When testing resistance in a circuit with an ohmmeter, _____. the ohmmeter is connected in parallel to the circuit and the circuit is turned on the ohmmeter is connected in series to the circuit and the circuit is turned on the circuit or component must first be disconnected from the power source, then the ohmmeter is connected in parallel with the component being tested

the circuit or component must first be disconnected from the power source, then the ohmmeter is connected in series with the component being tested

The wiring harness for the SIR [air bag] circuit has a _____ harness cover. red orange day glow green yellow

yellow