Mobile Electronics Certified Professional (MECP) Advanced Practice Test

These questions are part of the practice quiz. Start practicing

• During an RTA test, if a pink noise signal is played through the factory system, what does this output indicate?
• What happens if an insufficient ground is measured under load in an amplifier?
• In circuit analysis, which law states that the sum of the voltages around a closed loop is equal to zero?
• What color is the remote turn-on wire in an EIA color code compliant wiring harness adapter with a power antenna?
• A technician performs a series parasitic current drain test. Who is correct about the readings regarding a security system draining the battery?
• If a remote starter is armed, which technician's suggestion should be followed for addressing the RAP shutdown?
• How many Ohms separate RGB wires?
• What unique protection do power window closure modules offer that normal SPDT relays do not?
• When measuring the voice coil of a speaker with a DMM set to ohms while at rest, what is being measured?
• According to Kirchhoff's Voltage Law, what percentage of the available voltage will drop across the load if there is only one load component and a battery?
• When measuring alternator output voltage, at what engine speed should the measurement be taken?
• With a voltage divider consisting of 12V and two 1k ohm resistors, what is the output voltage?
• What must be installed whenever wiring passes through a metal firewall, if not already present?
• Using an oscilloscope on a vehicle's CAN bus, Technician A claims it can show message content while Technician B believes it can only monitor bus activity. Who is correct?
• What is the output power of a source unit that puts out 6 volts per channel into 4 ohms?
• Is a starter interrupt relay wired with Key Side on 87 and Starter Motor Side on 30 considered correctly wired as normally closed?
• How many liters are equivalent to an enclosure volume of 1 cubic foot?
• To test for a tach signal or injector pulse, to which measurement setting do you set the DMM?
• For LVDS connectors, how many wires correspond to an 8-pin configuration?
• Which statement regarding conventional automobile batteries is true?
• What does the term EBP stand for in relation to subwoofers?
• What is the effect of applying a damping material to metal resonating from loudspeakers?
• Which color wire contains the sync for vehicles operating on RGsB?
• A subwoofer with an EBP of 110 is indicative of what type of enclosure preference?
• How does the service activation status affect a wired satellite radio receiver?
• What type of Bluetooth device requires a PIN code to pair?
• When is a positive wire typically used in vehicle audio installations?
• Which measurement scale on a DMM is most accurate for testing potential difference under load?
• What does an RTA measure when connected to the speaker outputs of an OEM amplifier?
• What is the recommended practice for the placement of a security system control unit according to MECP guidelines?
• What happens to the output voltage across a resistor in a voltage divider if more load is added?
• Which device is recommended for measuring the audio signal waveform's voltage during audio system tuning?
• During troubleshooting, what is the first step after identifying a non-functioning remote starter?
• What is a common characteristic of an active High Speed CAN bus system?
• Which type of signal connector is most commonly used in automotive audio systems for input?
• During a parasitic current drain test, what is typically considered an acceptable current draw?
• In which type of passenger car will you find electrically separate parking light circuits?
• Which type of electronic component is characterized by emitter, collector, and base terminals?
• What does POF stand for in a mobile audio system?
• Which electrical unit is used to express the difference of potential in a circuit?
• A "hockey puck" style satellite radio antenna must have a suitable ground plane for optimal reception. Is this statement true or false?
• What is the outcome when measuring an insufficient ground in an amplifier setup?
• What type of measurement would a DMM display if used to test the output from an amplifier?
• Which of the following can cause resonance in an audio system's sheet metal?
• How many phases of AC are involved in the rectification of AC in a standard automotive alternator?
• At minimum, how many GPS satellites are visible to any receiver on Earth at any given time?
• What is the recommended tool for tucking the signal wire around the weather-stripping of a rear window for a satellite radio antenna?
• How much does +3dB increase the power output of an amplifier if the starting power is 200 watts?
• Is it true that High Speed CAN data bus networks can operate on a single copper wire if a short occurs in either the CAN Hi or CAN Lo network wires?
• What is the internal volume of a subwoofer enclosure with dimensions of H= 18.5", W= 15", and D= 27" using 3/4" thick material?
• In the context of Bluetooth devices, what is the name for the device which is discoverable and/or searchable?
• A capacitance value of 100,000 microfarads is equal to how many farads?
• In a positive switching, high current ignition system, which ignition switch circuit has +12V in the ACC and RUN positions but not during START?
• Does an EBP of 37 indicate a vented (ported) enclosure is preferred for a subwoofer?
• What does Kirchoff's Voltage Law (KVL) state regarding a DC series circuit?
• What type of crossover is recommended for a subwoofer?
• In a positive switching ignition system, which position(s) will an Ignition #2 circuit show 12 volts?
• When troubleshooting audio distortion, which element is usually the first to inspect?
• What is the recommended condition for the installation of a GPS antenna?
• What do you typically check to ensure the proper operation of a remote starter installation?
• What happens to the voltage across an inductor when the current flowing through it changes?
• What is the primary function of polarized capacitors used in aftermarket mobile audio systems?
• What is the standardized color for GVIF wire connector?
• What are the main conductors in an RGBS signal?
• What is the electrical power consumption of an amplifier drawing 15 amperes of current with a supply of 13.8 volts?
• Regarding remote starters, who is correct: Technician A who says the keysense wire needs power, or Technician B who says the transponder interface must be interfaced correctly?
• What is the value of a resistor abbreviated as 6.6k Ohm?
• What should you do to electronically shut down the RAP feature after manually shutting down a remote starter?
• What is the current flow through a closed circuit supplied with 14 volts and a resistance of 2 ohms?
• What is the MECP recommended practice for installing data wires in an alarm/remote start data interface?
• Which type of vehicles typically wrap electrical wiring in cloth tape?
• In which type of vehicle will you find vacuum door lock systems?
• Why are incandescent or LED test lights recommended for technicians?
• To measure the signal level of an analog audio signal, which measurement scale is required on a DMM?
• In the context of diagnosing CAN bus activity, what can an oscilloscope determine?
• If a subwoofer enclosure has a net internal volume of 1.75 cubic feet, how many liters is that approximately?
• In an aftermarket rear seat entertainment system, is it necessary to connect into the car's existing speakers for audio playback?
• What is the Federal Motor Vehicle Safety Standard relating to active headrest restraints?
• What is the name of the side of a silicon diode that has a line on it?
• How is a window control module wired to close the windows on a reverse polarity window motor?
• What is the primary source of power for all electronics in a gas engine vehicle when it is running?
• Where are passive crossovers intended to be placed in the audio signal path?
• What is the main purpose of the fuse installed on an amplifier at the battery?
• To measure parasitic current drain, what unit must the DMM display?
• Which test equipment is specifically used to analyze audio signal bandwidth?
• When current flows through an inductor, what is true about the magnetic field present?
• Who is correct about determining the exact model year of a vehicle using the VIN or the door jamb sticker?
• When ISO-DIN mounting an in-dash source unit, what is usually necessary for proper mounting?
• What must be true for a vehicle with a remote starter to start using the RS remote?
• What is the most appropriate tool to help release the locking clips or tabs on a wiring harness plug?
• In the NFPA 704 diamond system, what does the blue area represent?
• What is the primary function of an automotive battery in a combustion engine vehicle?
• What feature enhances satellite radio antenna reception?
• What does a DMM display if leads are reversed during a voltage measurement?
• What setting should the DMM be on when troubleshooting an amplifier suspected of not receiving an audio signal on the inputs?
• What does the screen of a DMM display when the red and black meter leads are reversed in a DC Voltage measurement?
• What color abbreviation represents a black wire on a European vehicle wiring schematic?
• Which terminals on an SPDT automotive relay serve as the Normally Open and Common terminals?
• What is the main purpose of resistors in aftermarket mobile audio systems?
• Do all 1996 and newer vehicles sold in the U.S. use a CAN BUS system for control of door locks and door triggers?
• What is the expected voltage drop from a diode isolator when measuring at the battery terminals, if multiple batteries are connected in parallel?
• Which of the following components is typically used to filter noise in speaker wiring?
• What is another name for a 6dB/Octave crossover?
• What type of door trigger circuit shows +12V when closed and 0V when the door is open?
• What does LVDS stand for?
• What is the proper significance of the color coding in wiring harnesses?
• What system was developed by the Federal Aviation Administration to augment the GPS and improve accuracy?
• Which signal type is commonly used to ascertain engine speed in modern vehicles?
• What are the four important conductors in an RGsB signal?
• What is the voltage measurement when two 12V batteries are connected in parallel with a test lead on the negative terminal of one battery and the positive terminal of the other?
• What setting should be used on a DMM to find voltage drops on amplifier grounds?
• For a correct installation of a roof mounted satellite radio antenna, which tool should be used?
• How many different values of resistance are present in GM VATS factory anti-theft systems?
• How many pins can be found on a LVDS plug?
• In a GM vehicle utilizing "GM LAN" Network communication, how is this system categorized?
• Which component is fundamental for the operation of the CAN bus system?
• In the diagram of an SPDT automotive relay, which terminals are the coil terminals?
• Which pin code is commonly associated with Bluetooth devices as mentioned by Technician A?
• When a dual 4-ohm DVC speaker is wired with coils in parallel, what DC resistance value does it yield to the amplifier?
• What is the voltage threshold for an automotive battery under Cold Crank Amp (CCA) rating at 0 degrees Fahrenheit?
• How do telematics systems utilize data communication?
• Based on an oscilloscope signal, who is correct if Technician A claims it's an audio signal and is clipping, while Technician B states it’s a data-bus signal in a dominant state?
• In an SPDT starter interrupt relay wired "Normally Closed", which two terminals connect to the starter wires?
• When asked about HD Radio, what does Technician A correctly say HD stands for?
• A vehicle with a remote starter can start with the RS remote but requires what additional component for functionality?
• Which Bluetooth sub-profile is necessary for a hands-free interface to access the phone's contact list?
• What scale must the DMM have to test diodes not connected in a circuit?
• What type of communication is typically used in modern vehicle telematics systems?
• What is the minimum number of GPS satellites required for precise latitude and longitude determination?
• In a 4-ohm parallel speaker configuration, how many total ohms does the configuration yield?
• What is an essential requirement when installing an aftermarket GPS system?
• In a positive switching, high current ignition system, which ignition switch circuit has +12V in the RUN and START positions but not during ACC?
• What is the typical symptom of a faulty RCA cable in an audio system installation?
• When installing a remote starter in a vehicle with a blade type ignition cylinder switch, what order of circuit activation must be followed to successfully start and run the vehicle?
• Which one of the following describes a vehicle's foot brake wire as tested for connection to a remote start?
• Is MECP's recommended practice for connecting a steering wheel control interface to use T-taps or 3M Scotch Locks?
• When wiring relays for a reversing polarity door lock system, which terminal connects to the motor side of the cut factory door lock wires?
• What indicates a reversing polarity door lock system without an onboard computer in the circuit?
• What function do parking light circuits provide when separated in certain vehicles?
• If both an amplifier and head unit bench tested fine but show no left channel audio in the vehicle, what could be inferred about the RCA audio cable testing 0.01 Ohm?
• Which wiring connection is critical for the safe operation of a remote starter?
• What type of crossover is appropriate for a tweeter?
• Regarding GPS navigation head unit installation, who correctly identifies the "speed pulse" connection?
• According to MECP guidelines, is it acceptable to untwist data wiring?
• What is the purpose of RGBHV conductors?
• For the installation of an RF communication antenna, what is the recommended practice?
• What type of signal measurement is important when troubleshooting audio equipment for signal presence?
• Reducing a 100 watt audio system's SPL output by 3dB results in how much power?
• What is the correct output to use on contact terminal 85 of a relay when integrating the clutch switch for a remote start in a manual transmission vehicle?
• In the scenario of a diesel engine vehicle for a remote starter installation, which technician is correct regarding wiring the tach signal?
• Which component serves as a barrier for undesired frequencies in an audio system?
• What is the nominal impedance of subwoofers wired in parallel as described?
• When troubleshooting audio systems, what is the primary purpose of a Digital Multimeter (DMM)?
• What is an acceptable amount of measured parasitic current draw with the car off and parked overnight?
• What is the expected current required to energize a Bosch SPDT relay with 12 volts and a coil resistance of 80 Ohms?
• For RF antenna installations, why is height important?
• What is the most effective way to add mass to control resonating sheet metal from a loudspeaker in an audio system?
• Which technician states an accurate problem about the keysense wire needing to be powered?
• Vehicles that operate on RGsB will be from which production years?
• When measuring an active High Speed (HS) CAN bus system, what should the combined voltages of the bus HI and LOW equal?
• Which description best fits a variable voltage automotive electrical circuit?
• Who is correct regarding the problem of a remote starter only functioning with the key in the Key cylinder?
• Is it true or false that AC ripple in a healthy automotive alternator is highest at idle RPM?
• What is the name of the signal that electrically reports engine speed?
• What measurement is indicated by setting mA?
• A customer complains of poor audio quality from a portable media audio device. Which initial diagnosis is valid?
• What type of connection is recommended for data wires in alarm/remote start systems?
• Which functionality must a head unit support for Bluetooth streaming audio from a smartphone?
• Is it acceptable to untwist existing data wiring to access connections when relocating a network device according to MECP?
• What does HD in HD Radio signify according to Technician A?
• Which property does a Hall-Effect clamp rely on when measuring current flow in a circuit?
• What is a coulomb equivalent to in terms of electrons?
• Which of the following statements about GPS systems is accurate?
• How many conductors are in RGBHV?
• What method is used for delivering satellite radio signals to compatible in-car receivers?
• What does a value of 0.01 Ohm indicate when tested on an RCA audio cable?
• When wiring multiple relays to trigger from a single low current output, how many 80-ohm coil relays can be safely connected at 12 volts if the output supplies 500mA of current?
• What occurs when a diode is operating normally in a forward biased condition?
• What is the electrical unit for resistance in a circuit?
• What does the internal volume calculation for an audio enclosure primarily affect?
• What type of component is primarily used to store electrical energy in a circuit?
• What is the GVIF male color connector from Sony manufacturers?
• What is the combined purpose of the sync conductors in RGBS?
• What does a purple (violet) wire represent in an EIA color code compliant wiring harness adapter?
• Which tool is recommended by MECP for checking audio signal bandwidth from an OEM head unit or amplifier?
• What color does the abbreviation WS represent in an OEM European vehicle wiring schematic?
• What is the primary function of inductors used in aftermarket mobile audio systems?
• A wired satellite radio receiver only broadcasts preview channels when which condition occurs?
• Which component is primarily responsible for managing high frequency cut-off in a speaker circuit?
• In Bluetooth pairing, what is a common default PIN code reported by Technician B?
• What unique feature does a permanently installed GPS unit have compared to portable navigation devices?
• What is the internal volume of an enclosure with outside dimensions of 15" (H) x 33" (W) x 11" (D) using 3/4" thick MDF?
• What is the effect of installing a single inductor in series between an amplifier's positive speaker output and the speaker?
• Which of the following conductors are included in RGBHV?
• What electronic component must accompany a remote starter's hard wired connections to replicate specific voltages on low current ignition wires?
• As car batteries age, what happens to their internal impedance?
• What trigger is used to turn off a Retained Accessory Power (RAP) Circuit?
• If a circuit measures 14 volts and 8 amps, what is the resulting electrical power consumption?
• Which type of filter is typically placed on the positive side of a component speaker?
• Which type of amplifier topology is the most efficient when all other factors are equal?
• What color is commonly associated with ground in RGsB systems?
• An inductance value of 1 Henry is equivalent to how many milliHenries?
• What is the importance of checking the battery voltage when troubleshooting electronic vehicle systems?
• How should extra cable length on GPS or satellite radio antennas be managed?