Exam 17: Map and Maf Sensors

Which of the following components measures the volume and density of the incoming air?

Technician A says that a heavy engine load results in high intake manifold vacuum and a high MAP sensor signal voltage. Technician B says that a MAP sensor uses a perfect vacuum (zero absolute pressure) in the sensor to determine the pressure. Which technician is correct?

If the MAF sensor fails, the PCM uses ________ to calculate fuel delivery needs.

As the altitude of the vehicle increases, barometric pressure ________.

Which of these tools could be used to test a MAP sensor?

An eight-wire mas airflow sensor senses all of these EXCEPT ________.

The MAF sensor is used mostly to determine the amount of ________ to deliver to the engine.

The component shown (shaded) has a crack or split in it. What would this cause?

Which of these can be used to measure the frequency (Hz) output of the MAF sensor?

Most MAP sensors produce what type of output signal?

Technician A says that pressure below atmospheric pressure is called vacuum and is measured in inches of Mercury (Hg). Technician B says that a manifold absolute pressure (MAP) sensor uses a low vacuum in the sensor to determine the pressure. Which technician is correct?

The output of a MAP sensor is reading 1.0 volt. What is the approximate engine vacuum in inches of Mercury (Hg)?

A MAP sensor is being tested. Technician A says that many MAP sensors also act as a barometric pressure sensor when the ignition switch is first turned on. Technician B says on many MAP sensors the signal voltage should increase when the vacuum at the sensor decreases. Which technician is correct?

The opening of the EGR valve pintle does NOT cause a change in the MAP sensor reading. This could cause ________.

Technician A says that a MAF sensor actually measures the density and amount of air flowing into the engine, which results in accurate engine control. Technician B says that a hot wire MAF sensor uses the electronics in the sensor itself to heat a wire 70°C above the temperature of the air entering the engine. Which technician is correct?

Dirt can affect all of these sensors, EXCEPT ________.

When testing a MAP sensor that produces an analog voltage signal with 18 in. hg. applied to the sensor, the sensor signal is l.4 volts. When 13 in. hg. is supplied to the sensor, the sensor signal should be which of these voltage values?

The MAP sensor is used when the OBD-II does a test of the ________ system.

A scan tool can be used to test a MAP sensor by monitoring the injector pulse width (in milliseconds) when ________ is being applied to the MAP sensor.