Chapter #34 - Review Questions

Technician A states that Hall-effect TPSs use a noncontact principle that makes them more reliable than potentiometer types. Technician B states that a Hall-effect TPS does not require an input voltage to function. Who is correct?

A only

Technician A states that engine overspeed rpm is usually programmed to the ECM as a hard value. Technician B states that the engine oil/coolant overheat temperature value was usually programmed to the ECM as a soft value because it would depend on the ambient temperatures. Who is correct?

A only

Technician A states that in some of the earliest engine management ECMs, the only method of changing customer options, such as idle shutdown duration and transmission ratios, was to replace the ECM PROM chip. Technician B states that in most current vehicle management systems, customer programmable options are written to ROM. Who is correct?

A only

The acronym that describes the internal computer component that executes program instructions is the:

CPU

Which of the following components conditions V-Ref?

ECM

To which of the following memory categories would customer data programming be written from an electronic service tool?

EEPROM

Which of the following input components would more likely use a variable capacitance- type sensor?

MAP

Technician A states that in most diesel engine ECMs, RAM data is lost whenever the engine is shut down. Technician B states that some systems write data to a special type of RAM that is nonvolatile because it connects directly to the battery. Who is correct?

both A & B

Technician A states that it is not unusual for the vehicle maximum speed to be programmed at a lower speed than maximum cruise speed. Technician B states that because fuel economy is so important in trucking operations, soft cruise is a popular option. Who is correct?

both A & B

Which of the following customer data programming fields could be described as a toggle option?

governor type

In a full authority diesel engine management system, EUI switching is performed by:

injector drivers

Technician A states that V-Ref and the injector driver voltage are usually managed by the ECM to the same voltage values. Technician B states that V-Ref is controlled by the vehicle battery and is not conditioned by the ECM. Who is correct?

neither A nor B

Technician A states that a disadvantage of a piezo actuator is that it requires a much higher current draw than comparable solenoid actuators. Technician B states that an advantage of piezo actuators is that they are much less bulky than comparable solenoids. Who is correct?

neither A nor B

When a Wheatstone bridge-type sensor is referred to, which of the following would correctly de-scribe it?

piezoresistive sensor

Which of the following components uses a voltage divider principle and can be used to signal accelerator pedal travel?

potentiometer

A Hall-effect sensor is usually responsible for signaling data concerning:

rotational or linear position

Induction pulse generators are used to input data concerning:

rotational speed

A thermistor is responsible for signaling data concerning:

temperature

Which of the following data retention media is electronically retained?

RAM

To which of the following memory categories would the master program for engine management be written in a typical truck engine ECM?

ROM