WorksheetsDSL-206 Chap 21: Body Electrical Systems-Instrumentation
Total questions: 20
Worksheet time: 10mins
Technician A says that the mechanical ground switches are used to indicate low fluid levels, low air pressure warning systems, or power divider engagement locks. Technician B says that electronic switches are most commonly used for warning lights. Who is correct?
a. Technician A
b. Technician B
c. Both Technician A and Technician B
d. Neither Technician A nor Technician B
Technician A says pneumatic switches are the most common way warning lights are illuminated in today's vehicles. Technician B says warning lights provide easily understood information to alert the equipment operator to potentially dangerous operating conditions. Who is correct?
a. Technician A
b. Technician B
c. Both Technician A and Technician B
d. Neither Technician A nor Technician B
If gauges do not respond with a prove-out sequence when ignition is switched on, a possible cause could be __________.
a. Loose connections at sender unit and/or gauge
b. The sender unit wires shorted to ground
c. The sender unit wire is disconnected
d. A defective stepper motor
Most gauges using stepper motors have __________ possible steps of positions between zero and full-scale deflection.
a. 3000
b. 3060
c. 1030
d. 1000
What type of gauge is not electrical because it depends on cables, air, or fluid pressure to operate?
a. Mechanical gauge
b. Bimetallic gauge
c. Electromagnetic gauge
d. Digital display gauge
In the __________ gauge design, the field coils are wound in series, but in opposite directions.
a. Bipolar motor
b. Two-coil
c. Stepper motor
d. Intelligent
Which of the following is an example of a gauge that can use D'Arsonval movement?
a. Tachometer
b. Speedometer
c. Voltmeter
d. Odometer
Technician A says resistive-type gauges are quickly checked by closing the circuit to the sending unit or opening the sending unit lead. Technician B says that when a circuit is opened, circuit resistance becomes low and will move a gauge to either its minimum or maximum reading. Who is correct?
a. Technician A
b. Technician B
c. Both Technician A and Technician B
d. Neither Technician A nor Technician B
Sending units are different from sensors, which are low-voltage electronic devices with __________.
a. No moving parts
b. Less resistance
c. A permanent magnet
d. More current
Temperature-sending units use __________ similar to the design of a coolant thermostat.
a. A bimetal arm
b. Proprietary software
c. A flexible bellow
d. A wax pellet
Inaccurate or fluctuating speedometer readings can be caused by other systems associated with the speedometer. Interference can originate from which of the following?
a. Cruise controls
b. Audio speakers
c. Magnetic metals
d. Warning lights
Older mechanical __________ used a pen and ink to plot speed on a rotating paper disk that completed one revolution in 24 hours.
a. Speedometers
b. Tachographs
c. Tachometers
d. Odometers
Speed limiters required by many jurisdictions are associated with __________ settings.
a. Tachograph
b. Speedometer
c. Tachometer
c. Tachometer
Which of these holds true for resistive touchscreens?
a. A unique voltage value is sensed by capacitors placed at the x and y coordinate edge of the screen.
b. Linear voltage is translated into coordinates and an input command goes to the screen microcontroller
c. Resistive touchscreens use only one electrically charged layer that typically is a glass panel with a transparent coating of indium metal.
d. Two flexible transparent sheets are separated by an air gap or microdot that closes like a switch when finger, object, or other pressure is applied to the screen.
__________ are made of rod-shaped molecules that are arranged in a parallel lattice-like structure.
a. Liquid crystals
b. Magnetic sensors
c. Transparent plates
d. Resistive film screens
Which of these is a diagnostic strategy if the gauge stays at minimum or maximum position?
a. Test terminating resistors
b. Check fuses and breakers
c. Measure CAN power and ground with voltmeter
d. Check harness, isolate shorts to ground, and repair
Which of the following is a possible symptom of a defective stepper motor?
a. Gauge stays at minimum or maximum value all the time
b. No data on CAN instrument gauge display
c. Erratic gauge readings
d. Gauges do not respond with a prove-out sequence when ignition is switched on
What is the possible cause of nonavailability of data on the CAN instrument gauge display?
a. Defective sending unit or gauge
b. Sender unit wires shorted to ground
c. Sender unit wires shorted to power
d. Missing terminating resistors
Gauges do not respond with a prove-out sequence when ignition is switched on. What could be the possible cause?
a. Defective sending unit
b. Missing terminating resistors
c. Defective stepper motor
d. Sender unit wires shorted to ground
Operation of a three-coil design gauge. The bucking coil progressively cancels the effect of the minimum reading coil as more current passes through the _____.
a. High coil
b. The sending unit
c. Low coil
d. Bucking coil
