Truck Electrical Circuit Fundamentals Part B 190404aB Flashcards
1
Q
- What component prevents all the warning lights from illuminating when one warning
light is illuminated?
a) fusible link
b) buzzer
c) relays
d) isolating diodes
A
d) isolating diodes
2
Q
- Explain how the alternator R terminal indicates that the alternator is not charging.
A
- By using the alternator (R) or relay terminal and a relay. The only time a voltage is
available from the relay terminal is when the alternator is generating an output. When
you turn the ignition switch on, with the engine not running, the warning lamp
illuminates; this occurs by means of current from the ignition switch passing through
the normally closed contacts of the relay. When the alternator starts to charge,
voltage from the alternator relay terminal energizes the relay windings. This moves
the armature within the relay from terminal 87a to terminal 87, opening the circuit.
This causes the light to go out.
3
Q
- List the three (3) types of analog gauges.
A
- a) balancing coil gauge
b) stepper motor gauge
c) air core gauge
4
Q
- How does a digital gauge receive its signal?
a) from fiber optic cable
b) by an analog signal from the sending unit
c) over the truck’s data link
d) by a capillary tube
A
- c) over the truck’s data link
5
Q
- A Hall effect sensor sends an amperage signal to the ammeter by:
a) measuring the current along the shunt.
b) using an integrated circuit amplifier.
c) reversing the current flow.
d) grounding the signal from the alternator.
A
- b) using an integrated circuit amplifier.
6
Q
- Calculate the PPM for a truck equipped with a rear axle ratio of 4.56, tire revs/mile of
518 and a chopper wheel with 16 teeth.
a) 25983
b) 34063
c) 37793
d) 46081
A
- c) 37793
7
Q
- What term describes the speed of data transfer over a network?
a) bits per second
b) baud rate
c) data transfer rate
d) protocol
A
- b) baud rate
8
Q
- What term describes the communication network that connects to all of the
multiplexed components of a vehicle system?
a) Controller Area Network
b) protocol
c) topology
d) data bus
A
- d) data bus
9
Q
- What term describes the logic structure of the control modules in which no single
module has priority over another?
a) Controller Area Network
b) protocol
c) topology
d) data bus
A
- c) topology
10
Q
- What te1m describes a common language communicated between control modules?
a) Controller Area Network
b) protocol
c) topology
d) data bus
A
- b) protocol
11
Q
- Multiplexing reduces the number of conductors used on heavy equipment by:
a) eliminating redundant outputs.
b) reducing the number of control modules.
c) using larger conductor gauges.
d) allowing control modules to share data for inputs.
A
- d) allowing control modules to share data for inputs.
12
Q
- What determines if an information bit is dominate (0) or recessive (1) on a J1939 data link?
a. between pins A and B
b. between pins A and G
c. between pins A and F
d. between pins F and G
A
b. between pins A and G
13
Q
- Which of the following identifies where a specific failure has occurred?
a. suspect parameter number (spn)
b. parameter group number (PGN)
c. failure mode identifier (FMI)
d. subsystem identifier (SID)
A
a. suspect parameter number (SPN)
14
Q
- When testing the J1939/CAN data link resistance, between which two pins do you take the resistance check?
a. pins A and B
b. pins C and D
c. pins E and F
d. pins G and H
A
b. pins C and D
15
Q
Which of the following modules control other modules?
a. switch expansion module (SEM)
b. expansion module (EXM)
c. chassis control module (CHM)
d. bulkhead control module (BHM)
A
d. bulkhead control module (BHM)
