Deck 11: Approach to Diagnostics

Question 1

Which device is NOT an essential tool of electronic system diagnosis?

A)Scan tool
B)Exhaust gas analyzer
C)DSO with a DMM capability and a current probe
D)Breakout box

Answer 1

D

Question 2

TSBs are being discussed. Technician A says a manufacturer-suggested repair may involve something as difficult as rehashing the PCM. Technician B says it may involve something as in-depth as replacing a PCM. Who is correct?

A)Technician A
B)Technician B
C)Both A and B
D)Neither A nor B

Answer 2

B

Question 3

Which item is NOT considered a tool for pinpoint testing?

A)DMM
B)Lab scope (DSO)
C)Scan tool
D)Battery load testers

Answer 3

C

Question 4

Diagnosing a loss of the computer's reference voltage is being discussed. Technician A says that the VREF signal should be between about 4.2 and 5.2 V. Technician B says that the VREF signal should be between about 5.2 and 9.6 V. Who is correct?

A)Technician A only
B)Technician B only
C)Both A and B
D)Neither A nor B

Question 5

What process is involved with on-board reprogramming?

A)The algorithm used to obtain the DC equivalent value
B)The process of preventing two or more messages from colliding on the data bus
C)Loading the reflash file to the appropriate control module via the vehicle's DLC
D)Removal of the control module from the vehicle

Question 6

A technician is capturing a current waveform for a load component on the positive side of a circuit. The current waveform shows higher-than-normal current flow. Which statement is true?

A)The windings within the component being tested may be shorted.
B)The waveform should be captured on the negative side of the circuit due to increased current flow on the positive side of the circuit.
C)A loose connection or other high resistance may exist within the controlling circuit.
D)An open may exist within the load component.

Question 7

Current ramping is a diagnostic procedure that is best suited for diagnosing problems associated with:

A)circuitry
B)switches
C)load components
D)input sensors

Question 8

Technician A says that a self-test DTC identifies a hard fault. Technician B says that a memory DTC always represents a soft fault. Who is correct?

A)Technician A only
B)Technician B only
C)Both A and B
D)Neither A nor B

Question 9

Which of these statements is NOT a recommendation when using a flowchart?

A)Read and follow the test instructions.
B)Skip selected identifiable test steps.
C)Be sure of your equipment: Does your jumper wire have continuity?
D)Make the repair as indicated in the final step.

Question 10

What scenario is indicated by a loss of more than about 2 in. Hg of intake manifold vacuum as the RPM is increased?

A)The level of current flow
B)A 50 percent duty cycle
C)Excessive exhaust backpressure
D)The volume of air entering the engine

Question 11

If an OBD II PCM has set a catalyst efficiency code, all of the following pre-checks should be performed before condemning the converter EXCEPT for:

A)checking the exhaust system for any leaks
B)using a scan tool to check for O₂ sensor codes
C)visually checking the O₂ sensors for cracked housings
D)verifying that the engine does not have excessive cycling

Question 12

If the engine cranks but does not start, what should be checked?

A)Primary ignition
B)Both secondary and primary ignition
C)Secondary ignition
D)Either secondary or primary ignition

Question 13

Checking for excessive circuit resistance is being discussed. Technician A says voltage drop testing is used to identify excessive unwanted resistance in the circuitry. Technician B says measuring resistance is the most accurate method. Who is correct?

A)Technician A
B)Technician B
C)Both A and B
D)Neither A nor B

Question 14

Pinpoint testing a DTC is being discussed. Technician A says that to verify monitor readiness status, you should use a scan tool. Technician B says that if a monitor is displayed on the scan tool as N/A, it does not apply to the vehicle you are working on. Who is correct?

A)Technician A only
B)Technician B only
C)Both A and B
D)Neither A nor B

Question 15

Which term represents an online diagnostic information service designed to help the automotive service technician in diagnosing difficult problems?

A)Identifix
B)Ifixit
C)Icracked
D)Technicianonline

Question 16

When using an electrical schematic, the first step is to:

A)identify the powers and grounds
B)identify the components
C)identify the input and output circuits
D)identify any data buses used for communication between computers

Question 17

Which statement is true concerning a breakout box?

A)It provides the same functionality as a scan tool.
B)It is normally used to reprogram the PCM.
C)It allows pinpoint tests of electronic system circuits without back-probing
D)Both A and B

Question 18

A vehicle equipped with OBD II is being diagnosed with a scan tool. There are three codes stored. Technician A says to clear the codes and drive the vehicle to see if any reappear. Technician B says the codes may be related to the same problem. Who is correct?

A)Technician A
B)Technician B
C)Both A and B
D)Neither A nor B

Question 19

Three-in-one diagnostic tools are being discussed. Technician A says the Snap-on Modis can be configured to include a scan tool, a DSO, and an exhaust gas analyzer. Technician B says the OTC Genisys can be configured to include a scan tool, a DSO, and an exhaust gas analyzer. Who is correct?

A)Technician A
B)Technician B
C)Both A and B
D)Neither A nor B

Question 20

Current ramping can be used to identify problems with a motor:

A)that will not operate at all due to a total loss of brush-to-armature contact internally
B)that has intermittent symptoms or is not operating at peak efficiency
C)that is located in a circuit with a blown fuse
D)that is located in a circuit that is disconnected from the battery