On-board Diagnostics (Obd) Quiz - Know More About Vehicles

1. Automotive emissions cause harm to all of these EXCEPT:

The air we breathe.

The environment.

Modern technology.

Human health.

Modern technology is not harmed by automotive emissions.

Explanation

Modern technology is not harmed by automotive emissions.

2. Which of these is the best place to start gathering information and planning a diagnostic pathway based on suspected systems and components?

The owner's manual

Diagnostic trouble codes (DTCs) and customer information

The service manual

Technical service bulletins

Always start with customer experiences, reading DTC's, and driving the vehicle yourself to confirm these experiences.

Explanation

Always start with customer experiences, reading DTC's, and driving the vehicle yourself to confirm these experiences.

3. To ensure that a vehicle malfunction is identified and repaired correctly, always follow

Aftermarket service manuals.

Original equipment manufacturer (OEM) diagnostic flow charts.

Aftermarket training manuals.

OEM owners' manuals.

The best, most accurate and up-to-date information for servicing vehicles is found in the OEM diagnostic flow charts.

Explanation

The best, most accurate and up-to-date information for servicing vehicles is found in the OEM diagnostic flow charts.

4. Which of these provides constant yet simplified interconnectivity between on-board vehicle modules?

Discreet wiring

A controlled area network bus (CAN-bus)

A scan tool

A personal computer (PC)

Constant binary code is shared between control modules.

Explanation

Constant binary code is shared between control modules.

5. Which of these is a device able to electronically communicate with and extract data from the vehicle's one or more on-board computers?

An oscilloscope

A scanner

A graphing calculator

A power probe

A scanner links to a vehicle and gets important, DTC/MIL related information.

Explanation

A scanner links to a vehicle and gets important, DTC/MIL related information.

6. In what year was on-board diagnostics II (OBDII) systems enacted nationwide?

1973

1981

1975

1996

1996 is the year of OBDII implementation.

Explanation

1996 is the year of OBDII implementation.

7. A drive cycle includes all of these EXCEPT:

Vehicle start-up.

Vehicle acceleration.

Vehicle cruise.

Vehicle cold soak.

Cold soak is when an engine sits without running, until it is as cold as the ambient temperature.

Explanation

Cold soak is when an engine sits without running, until it is as cold as the ambient temperature.

8. Engine related freeze-frame data can be accessed from the vehicle's:

Electronic brake control module (EBCM).

Transmission control module (TCM).

Power train control module (PCM).

Body control module (BCM).

The PCM or ECM are responsible for monitoring and storing engine related processed and faults.

Explanation

The PCM or ECM are responsible for monitoring and storing engine related processed and faults.

9. Harmful tailpipe emissions include all of these EXCEPT:

Carbon monoxide (CO).

Hydrocarbons (HCs).

Particulate matter (PM).

Oxygen (O2).

O2 is a naturally occurring, non-harmful emission.

Explanation

O2 is a naturally occurring, non-harmful emission.

10. Fault codes on today's vehicles are categorized by vehicle:

System.

Year.

Make.

Model.

In contemporary vehicles, DTC's are categorized by system.

Explanation

In contemporary vehicles, DTC's are categorized by system.

11. A scan tool detects a communications fault in the controlled area network bus (CAN-bus). Which of these diagnostic trouble codes (DTCs) would MOST likely be stored?

P0402

U0021

B0092

C0035

"U" is the designation for communication faults.

Explanation

"U" is the designation for communication faults.

12. Never jump battery or power supply voltages to an actuator while it is connected to its:

Control circuit.

Mother board.

Mechanical linkage.

Driven component.

Leaving a controller hooked up when jumping to power to operate an actuator will allow the current to potentially also go into the controller.

Explanation

Leaving a controller hooked up when jumping to power to operate an actuator will allow the current to potentially also go into the controller.

13. On-board diagnostics II (OBDII) data are retrieved by connecting a scan tool to the:

Malfunction indicator lamp (MIL).

Data link connector (DLC).

Diagnostic trouble code (DTC).

Power train control module (PCM).

The DLC is the interface between the vehicle and the scan tool.

Explanation

The DLC is the interface between the vehicle and the scan tool.

14. Tech A says that the on-board diagnostics II (OBDII) system is designed to set fault codes if the vehicle exceeds the limits programmed within the vehicle system. Tech B says that the EPA Federal Test Procedure pass and fail points are the same for every vehicle. Who is correct?

Tech A

Tech B

Both Techs A and B

Neither Tech A nor B

Conditions that are outside preprogrammed values causes the DTC/MIL to illuminate. The test procedure for every vehicle is not the same.

Explanation

Conditions that are outside preprogrammed values causes the DTC/MIL to illuminate. The test procedure for every vehicle is not the same.

15. A diagnostic trouble code (DTC) indicates that a vehicle has experienced all of these EXCEPT:

An emissions related fault.

A broken “hard part.”

An illuminated malfunction indicator lamp (MIL).

A DTC will get you headed in the correct direction, but a technician must confirm that a part is broken before replacing it.

Explanation

A DTC will get you headed in the correct direction, but a technician must confirm that a part is broken before replacing it.

16. Tech A says that the original equipment manufacturer (OEM) offer scan tools to service their specific line of vehicles. Tech B says that scan tools supplied by aftermarket tool and equipment providers usually provide greater functionality. Who is correct?

Tech A

Tech B

Both Techs A and B

Neither Tech A nor B

All OEM offer their own, proprietary scan tools that most often offer the greatest functionality for advanced testing and inspecting of DTC related concerns.

Explanation

All OEM offer their own, proprietary scan tools that most often offer the greatest functionality for advanced testing and inspecting of DTC related concerns.

17. A fault code that begins with the letter "P" would MOST likely address a fault in the:

Exhaust system.

Power door lock wiring.

HVAC system.

Interior lighting system.

The "P" in the DTC indicates a fault in the powertrain system.

Explanation

The "P" in the DTC indicates a fault in the powertrain system.

18. State-run emission inspection stations in the United States will sometimes allow a vehicle to pass an emission inspection under any of these situations EXCEPT:

A monitor has run and failed.

A monitor has run and is pending.

One monitor has not run.

Two monitors have not run.

Some States may allow a vehicle with an emissions monitor that has run and not failed, a pass on state regulated emissions.

Explanation

Some States may allow a vehicle with an emissions monitor that has run and not failed, a pass on state regulated emissions.

19. Tech A says that a graphing multimeter may be used to verify signals going to and from electrical and electronic components. Tech B says that digital storage oscilloscope may be used to verify signals going to and from electrical and electronic components. Who is correct?

Tech A

Tech B

Both Techs A and B

Neither Tech A nor B

Both of the listed tools can be used to verify electrical signals, but the oscilloscope is a much more sophisticated piece of diagnostic equipment.

Explanation

Both of the listed tools can be used to verify electrical signals, but the oscilloscope is a much more sophisticated piece of diagnostic equipment.

20. Electrical circuits in the on-board diagnostics (OBD) system are being diagnosed. Tech A says that it's important to check for voltage drops on the power side of the circuit. Tech B says that it's important to check for voltage drops at the circuit ground connections. Who is correct?

Tech A

Tech B

Both Techs A and B

Neither Tech A nor B

The voltage drop test is one of the most important electrical tests, and can be performed on any complete circuit.

Explanation

The voltage drop test is one of the most important electrical tests, and can be performed on any complete circuit.

21. A fault code that begins with the letter "B" would MOST likely address a fault in the:

Ignition system.

Exhaust system..

Taillight circuit.

Transmission

The "B" in a MIL indicates that the concern is a body related fault.

Explanation

The "B" in a MIL indicates that the concern is a body related fault.

22. Continuous monitors are run for systems that could:

Contribute to major emissions failures.

Cause a safety related problem.

Cause an inconvenience for the driver.

Cause other systems to fail.

Individual monitors are continuous and are subsystems of ECM/PCM processes.

Explanation

Individual monitors are continuous and are subsystems of ECM/PCM processes.

23. A vehicle is known to be out of compliance with clean air regulations whenever:

It flunks a safety inspection.

Its registration has expired.

A red light is illuminated on the instrument panel.

Its malfunction indicator lamp (MIL) is illuminated.

An illuminated MIL would indicate an emissions related fault that would cause excessive, out of compliance emissions.

Explanation

An illuminated MIL would indicate an emissions related fault that would cause excessive, out of compliance emissions.

24. Tech A says that many actuators operate on voltages supplied by the system computer. Tech B says that actuators may operate on at voltages other than battery voltage. Who is correct?

Tech A

Tech B

Both Techs A and B

Neither Tech A nor B

Actuators are not only driver commanded. A controller may also operate actuators. These circuits, at times, may operate on voltages other than battery voltage.

Explanation

Actuators are not only driver commanded. A controller may also operate actuators. These circuits, at times, may operate on voltages other than battery voltage.

25. On-board diagnostic (OBD) systems help the service tech do all of these EXCEPT:

Work more efficiently.

Determine exactly where faults exist.

Take the guesswork out of diagnosing vehicle problems.

Access data for today's sophisticated vehicles.

An accomplished technician still needs to run tests, and confirm any fault the vehicle "thinks" it may have.

Explanation

An accomplished technician still needs to run tests, and confirm any fault the vehicle "thinks" it may have.

26. Tech A says that it is possible for a vehicle to have one fault that causes yet another fault to set a code. Tech B says that the test light, an analog voltmeter, and a logic probe are worthwhile diagnostic tools. Who is correct?

Tech A

Tech B

Both Techs A and B

Neither Tech A nor B

If certain parameters are so out of whack. it may lead to multiple codes setting. An analog voltmeter is not something that is commonly used in the automotive trade.

Explanation

If certain parameters are so out of whack. it may lead to multiple codes setting. An analog voltmeter is not something that is commonly used in the automotive trade.

27. When it comes to troubleshooting an on-board diagnostic (OBD) code, the tech's best tools include all of these EXCEPT:

A test light.

A digital volt-ohmmeter (DVOM).

A lab scope.

A scan tool.

A test light does not give us sufficient information for these sophisticated concerns or issues.

Explanation

A test light does not give us sufficient information for these sophisticated concerns or issues.

28. Which of these has reduced the weight and expense of wire bundles in today's automobiles?

Aluminum wiring

Shared circuits

High-voltage circuits

Controller area networks

A CAN and its system of nodes and circuitry reduce the overall weight of vehicles.

Explanation

A CAN and its system of nodes and circuitry reduce the overall weight of vehicles.

29. Which of these pollutants is caused by fuel or oil vapors?

Volatile organic compounds (VOCs)

Hydrocarbons (HCs)

Carbon monoxide (CO)

Particulate matter (PM)

VOC's are the harmful emissions created by fuel AND oil.

Explanation

VOC's are the harmful emissions created by fuel AND oil.

30. Which of the following types of data helps a tech to determine the actual conditions under which a fault code is set?

Technical service bulletin (TSB) data

Diagnostic trouble code (DTC) data

Service manual data

Freeze-frame data

Freeze frame data are the conditions that were occurring when the DTC was set.

Explanation

Freeze frame data are the conditions that were occurring when the DTC was set.