1. A serial data line or bus is used for which of the following purposes?
C. Transmit pulses from the ignition primary coil to the tachometer
12. GM Class 2 communication toggles between
B. 0 and 12 V.
3. Technician A says that module communications networks are used to reduce the number of wires in a vehicle. Technician B says that a communications network is used to share data from sensors, which can be used by many different modules. Which technician is correct?
A. Technician B only
4. A magnetic field is created around a wire when
A. the wire is connected between two grounds.
5. In most automotive electrical circuits, a relay is used in which of the following situations?
C. A lower-voltage circuit controls a higher-voltage circuit.
6. A diagnostic scan tool connects to the vehicle using the
C. data link connector.
7. A diode with high resistance or an infinite reading in both directions is
C. reverse biased.
8. Two technicians are discussing how capacitors work. Technician A says that, in an open circuit, a capacitor will hold its charge until it's connected to an external circuit. Technician B says that theoretically a capacitor will hold its charge indefinitely. Who is correct?
A. Technician A
9. All of the following can be added to a circuit to reduce electromagnetic interference, except
C, a diode.
10. Technician A says when you push the horn button, electromagnetism moves an iron bar inside the horn, which opens and closes contacts in the horn circuit. Technician B says most vehicle horn circuits use a relay. Which technician is correct?
B. Both Technician A and Technician B
11. A/an _______ is a material with four electrons in the valence ring.
D. conductor
1. Technician A says that dynamic voltage is the voltage (usually of a battery) that exists without a load being applied. Technician B says that open circuit voltage (OCV) is the voltage of the power source (battery) with the circuit in operation. Who is correct?
A. Both Technicians A and B
2. A technician connects one lead of a digital voltmeter to the positive (+) terminal of the battery and the other meter lead to the battery terminal (B) of the starter solenoid and then cranks the engine. During cranking, the voltmeter displays a reading of 878 mV. Technician A says that this reading indicates that the resistance of positive battery cable is too high. Technician B says that this reading indicates that the starter is defective. Which technician is correct?
B. Technician A only