Deck 12: Instrumentation and Warning Lampsinstrumentation and Warning Lamp System Diagnosis and Repair

Question 1

A gauge that reads high when the ignition switch is placed in the RUN position indicates there is an open in the sending unit circuit.

Answer 1

False

Question 2

Before removing the instrument panel, always disconnect the battery negative cable.

Answer 2

True

Question 3

If equal voltage is applied to both sides of a lamp, the lamp remains off because current cannot flow.

Answer 3

True

Question 4

The head-up display (HUD) displays visual images onto radio face.

Question 5

Technician A says a tachometer is used to measure drive shaft speed. Technician B says a tachometer receives its signal from the plus side of the ignition coil. Who is correct?

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

Question 6

On most vehicles, oil pressure changes are monitored by a piezoresistive sensor.

Question 7

Equal pressure in the brake hydraulic system will cause the brake warning light to come on.

Question 8

Federal and state laws prohibit changing the correct mileage on the odometer.

Question 9

Electromagnetic gauges use heat to produce needle movement.

Question 10

Technician A says, if the speedometer is not operating and the BCM and/or cluster module passes the self-test, the fault may be in the VSS circuit. Technician B says if the speedometer works but the odometer does not, the vehicle speed sensor likely is the problem. Who is correct?

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

Question 11

Technician A says a conventional analog instrumentation is more accurate than a digital instrumentation. Technician B says a digital instrumentation displays an average of the readings received from the sensor. Who is correct?

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

Question 12

Technician A says if all gauges are not operating, check the fuse. Technician B says only one gauge will be affected if the instrument cluster ground is open. Who is correct?

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

Question 13

Technician A says depending on the manufacturer, a new IC chip may be programmed to display the last odometer reading. Technician B says some manufacturers provide for replacement of the IC chip if it fails. Who is correct?

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

Question 14

Technician A says a ground in the circuit between the indicator light and the pressure switch could cause the oil pressure light to stay on when the engine is running. Technician B says an open in the pressure switch could cause the oil pressure light to stay on. Who is correct?

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

Question 15

Most EICs have a prove-out display each time the ignition switch  is turned on.

Question 16

The fuel gauge of a digital instrument cluster is missing two segments of its numerical display. Technician A says the cluster has excessive ground circuit resistance. Technician B says the cluster needs to be replaced. Who is correct?

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

Question 17

Technician A says air core electromagnetic gauges and quartz swing needle displays are similar. Technician B says in quartz needle displays, the A coil is connected to the system voltage and the B coil receives a voltage proportional to input frequency. Who is correct?

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

Question 18

Technician A says in most electromagnetic gauges, if the sending unit resistance is low, the gauge will read low. Technician B says in most bimetallic gauges, if the sending unit resistance is low, the gauge will read high. Who is correct?

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

Question 19

Technician A says needle movement in a three-coil gauge is the result of the interaction of three electromagnets and the total field effect upon a permanent magnet. Technician B says interaction of a permanent magnet and an electromagnet, and the total field effect causes the needle movement in the d'Arsonval gauge. Who is correct?

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

Question 20

It is normal for some electromagnetic gauges to remain at their last position when the ignition is turned off.

Question 21

A vehicle's electronic digital fuel gauge is always indicating a full tank. All of the other instrument gauges are operating correctly. Which of the following is the most likely cause of this problem?

A) Excessive resistance in the cluster power supply circuit
B) Faulty cluster ground circuit
C) Shorted fuel gauge sender unit
D) High resistance in the fuel gauge sender circuit

Question 22

There are three types of sending units associated with electromechanical gauges: a thermistor, a piezoresistive sensor, and a mechanical ____ resistor.

A) open
B) variable
C) actuator
D) assembly

Question 23

Unlike gauge sending units, the sending units for a warning light are nothing more than simple ____.

A) switches
B) thermistors
C) lamps
D) resistors

Question 24

Technician A says when testing a system using an IVR, use a voltmeter to test for regulated voltage at a common point. Technician B says if regulated voltage is within specifications, you must replace the printed circuit board. Who is correct?

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

Question 25

Technician A says a normally open switch is used in most coolant temperature warning light circuits. Technician B says most oil pressure warning circuits use a normally closed switch. Who is correct?

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

Question 26

The electromechanical gauge acts as a(n) ____since the gauge reading changes with variations in resistance.

A) voltage resistor
B) ammeter
C) ohmmeter
D) analog gauge

Question 27

Electromagnetic gauges produce needle movement by magnetic forces instead of ____.

A) resistance
B) pressure
C) heat
D) mechanics

Question 28

On most systems, the odometer and speedometer receive their input from the vehicle ____ sensor.

A) motion
B) tire diameter
C) motor
D) speed

Question 29

Which of the following is NOT true about a quartz analog speedometer system?

A) The signal from the PM generator is a DC frequency.
B) The signal from the vehicle speed sensor is modified by the VSS buffer.
C) This system uses an A/D converter.
D) The signal from the vehicle speed sensor is an AC voltage.

Question 30

Technician A says the thermistor sensor measures pressure. Technician B says a voltmeter is used to test a thermistor sensor unit. Who is correct?

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

Question 31

Which of the following is NOT contained in a three-coil gauge?

A) A bucking coil
B) A low-reading coil
C) A high-reading coil
D) A non-reading coil

Question 32

What usually controls an oil pressure warning lamp?

A) Voltage drop
B) A ground switch
C) A ground sensor
D) Any of the above

Question 33

Which of the following is NOT true about a quartz analog speedometer system?

A) The signal from the PM generator is a DC frequency.
B) The signal from the vehicle speed sensor is modified by the VSS buffer.
C) This system uses an A/D converter.
D) The signal from the vehicle speed sensor is an AC voltage.

Question 34

Computer-driven quartz swing needle displays are similar in design to the ____ electromagnetic gauges used in conventional analog instrument panels.

A) d'Arsonval
B) three-coil
C) two-coil
D) air-core

Question 35

Most electronic instrument clusters (EICs) have a(n) ____ display each time the ignition switch is turned on.

A) actuator
B) status
C) prove-out
D) self-diagnostic

Question 36

A(n) ____ is a device that displays the measurement of a monitored system by the use of a needle or pointer that moves along a calibrated scale.

A) actuator
B) gauge
C) switch
D) sensor

Question 37

The sending unit is the ____ for the gauge.

A) control module
B) sensor
C) ammeter
D) switch

Question 38

A vehicle's electronic digital fuel gauge is always indicating a full tank. All of the other instrument gauges are operating correctly. Which of the following is the most likely cause of this problem?

A) Excessive resistance in the cluster power supply circuit.
B) Faulty cluster ground circuit.
C) Shorted fuel gauge sender unit.
D) High resistance in the fuel gauge sender circuit.

Question 39

A gauge that constantly reads low when the ignition switch is in the RUN position indicates an open in the ____.

A) sending unit
B) ignition switch
C) gauge circuit
D) fuse

Question 40

The computer-driven instrument cluster uses a microprocessor to process information from various sensors and to control the ____.

A) gauge display
B) trouble codes
C) transducer
D) powertrain

Question 41

In most vehicles equipped with a digital fuel gauge, as the fuel level decreases what will happen to the fuel sender resistance?

Question 42

Digital instrument clusters use what type of displays to notify the driver of monitored system conditions.

Question 43

What type of symbols are used to represent the gauge function on electronic instrument panels?

Question 44

How is the maintenance minder reset?

Question 45

What is the most common type of fuel level sending unit?

Question 46

What are the most common types of displays used on electronic instrument panels?

Question 47

The electromechanical odometer uses a(n) ____stepper motor that receives control signals from the speedometer circuit.

A) AC
B) DC
C) oscillating
D) negative

Question 48

A(n) ____ is an instrument that measures the speed of the engine in revolutions per minute (rpm).

A) speedometer
B) odometer
C) tachometer
D) H-gate

Question 49

What is "pinion factor?"

Question 50

A ____ system displays visual images onto the inside of the windshield in the driver's field of vision.

A) vacuum fluorescent light
B) holographic combiner
C) movie projector
D) head-up display

Question 51

What is the purpose of the head-up display?

Question 52

Explain the operation of computer-driven warning lamps.

Question 53

List the four types of electromagnetic gauges.

Question 54

How would you test a warning lamp that does not come on during the prove-out on a system with a normally open switch?

Question 55

What must be done if the odometer needs to be replaced?

Question 56

What additional procedures may be necessary if the instrument panel requires replacement?

Question 57

What is the purpose of the instrument voltage regulator (IVR)?

Question 58

All gauges require the use what type of sending unit?

Question 59

The service minder is activated at 3,000 miles after the last oil change even though the service interval is set for 6,000 miles. Technician A says it is possible the minder came on due to heavy engine loads. Technician B says the vehicle speed sensor is not reading accurately. Who is correct?

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

Question 60

Digital instrument clusters use digital and ____ displays to notify the driver of monitored system conditions.

A) linear
B) analog
C) ISO symbol
D) LED