Biology Forums - Study Force

1.   Technician A says that nonemission-related codes that make the malfunction indicator lamp (MIL) illuminate are called "Type A" codes. Technician B says that emission-related codes that illuminate the MIL after the first fault are called "Type A" codes. Who is correct?
     
A. Neither Technician A nor B
B. Technician B
C. Technician A
D. Both Technicians A and B

3.   The first character of a diagnostic trouble code (DTC) indicates the vehicle system. Which one of the letters below refers to the chassis and transfer cases?
     
A. C
B. U
C. P
D. B

4.   Technician A says that it's a good idea to perform a test drive before attempting repairs. Technician B says that it's a good idea to let the customer accompany you on the test drive. Who is correct?
     
A. Neither Technician A nor B
B. Technician B
C. Technician A
D. Both Technicians A and B

6.   Technician A says that OBD-II systems include generic as well as vehicle manufacturer's specific diagnostic trouble codes (DTCs) and scan data displays. Technician B says that OBD-II systems have common DTCs. Who is correct?
     
A. Technician B
B. Technician A
C. Both Technicians A and B
D. Neither Technician A nor B
 

7.   An OBD-II system interprets a disconnected spark plug as a misfire that could damage the three-way catalyst. The ECM or PCM will most likely trigger the malfunction indicator lamp (MIL) on the _______ trip.
     
A. second
B. fourth
C. first
D. third

8.   Technician A says that generic scan tools must be able to read all generic OBD-II codes. Technician B says that all generic scan tools must be able to read manufacturer OBD-II trouble codes. Who is correct?
     
A. Technician B
B. Both Technicians A and B
C. Technician A
D. Neither Technician A nor B
 

9.   All of these concerns can be diagnosed using the paper test except for a
     
A. burned valve.
B. cracked exhaust manifold.
C. bad spark plug wire in the ignition system.
D. faulty injector on a multiport engine.
 

10.   A vehicle fails an HC emission test at idle and 2,500 rpm, and the engine has an acceleration stumble. The heated oxygen sensor (HO2S) voltage is 0.1–0.3 volts on a scan tool, and the injector pulse width is high. No diagnostic trouble codes (DTCs) are found. When propane is directed into the air intake, HO2S voltage immediately increases and the injector pulse width decreases. The most likely cause of this problem is
     
A. a defective powertrain control module (PCM).
B. an opening in the O2 sensor signal wire.
C. a defective O2 sensor.
D. low fuel-pump pressure.

11.   An engine you're servicing has electronically controlled cooling fans. Cooling fan 1 doesn't work but cooling fan 2 does. Which of the following could be the cause?
     
A. Short at circuit 339, pink/black wire
B. Open at ECM Terminal A9
C. Open at ECM Terminal A3
D. Short at circuit 67, light blue wire

12.   The powertrain control module (PCM) or engine control module (ECM) will automatically clear a diagnostic trouble code (DTC) if there are no additional faults detected after
     
A. eighty warm-up cycles.
B. the criteria to clear codes is reached.
C. two consecutive trips.
D. five key-on/key-off cycles.
 

13.   Technician A says that a new replacement part is always good. Technician B says that sometimes recent repair work will be the cause of a complaint. Who is correct?
     
A. Both Technicians A and B
B. Technician B
C. Technician A
D. Neither Technician A nor B

14.   Technician A says that the last step in the diagnostic process is to verify the problem. Technician B says that the second step is to perform a thorough visual inspection. Who is correct?
     
A. Technician B
B. Neither Technician A nor B
C. Technician A
D. Both Technicians A and B

15.   Technician A says that on-board self-diagnostics test mode procedures should be conducted on a cold engine. Technician B says that many diagnostic trouble codes (DTCs) will monitor items only when the engine control system is in closed loop. Who is correct?
     
A. Neither Technician A nor B
B. Technician B
C. Both Technicians A and B
D. Technician A

16.   Technician A says that when the malfunction indicator light (MIL) or service engine light is on, you should retrieve the diagnostic trouble code (DTC) and follow the manufacturer's recommended procedure. Technician B says that all OBD-II monitors must have the enable criteria achieved before a test is performed. Who is correct?
     
A. Technician A
B. Both Technicians A and B
C. Technician B
D. Neither Technician A nor B

17.   What OBD-II term applies when all enabling standards for a specific diagnostic trouble code (DTC) are met?
     
A. Well-tuned engine
B. Warmed-up engine
C. Trip criteria
D. Freeze frame

18.   An OBD-II vehicle fails an emission test with high CO and HC emissions. Technician A says that the cause may be low fuel pressure. Technician B says the cause may be a restricted return line on the fuel supply system. Who is correct?
     
A. Neither Technician A nor B
B. Both Technicians A and B
C. Technician B
D. Technician A

19.   A U-type diagnostic trouble code (DTC) indicates a problem with the
     
A. engine or transmission.
B. body.
C. network.
D. chassis.
 

20.   You're diagnosing a hard-starting vehicle and installing a fuel pressure gauge. When the engine is shut off, the fuel pressure drops rapidly. Technician A says that a fuel injector could be leaking. Technician B says that the fuel pump may have a defective check valve. Who is correct?
     
A. Technician B
B. Technician A
C. Neither Technician A nor B
D. Both Technicians A and B
 

This information might help you choose the right option

C for chassis!

D, I'm guessing.

B -- https://en.wikipedia.org/wiki/OBD-II_PIDs

C

P = Powertrain B = Body C = Chassis U = Undefined

I'll choose C

B

When you fail because of high limits of HC or hydrocarbons, it means there is raw fuel that is being sent out the tailpipe because your engine isn't converting the fuel to energy. The raw fuel actually washes the protective layer of oil off moving parts inside your engine and contributes to engine wear which can lead to premature failure. Some common causes are spark plugs, spark plug wires, misadjusted timing or vacuum leaks.

When you fail because your CO or carbon monoxide is too high, that means the fuel and air ratio is way off and there is evidence of incomplete combustion or burning of the air/fuel mixture. Most of the common causes relate to the carburetor or the fuel delivery system. A CO failure will always be rooted in the carburetor or fuel injection system. CO failures are not fixed with spark plugs.

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