Question 1

What unit of measure is often used to express the amount of intake air measured by the Mass Air Flow (MAF) sensor?

Accepted Answer

The Mass Air Flow (MAF) sensor typically measures the amount of air entering the engine in grams per second (gps).

Question 2

Some vehicle manufacturers specifically say not to clean the MAF sensors on their vehicles and to instead replace them if they are not reading correctly.

Accepted Answer

Some manufacturers recommend replacing MAF sensors instead of cleaning them due to the risk of damage or improper cleaning affecting sensor performance.

Question 3

Which of the following statements is True about the location of Mass Air Flow (MAF) sensors?

Accepted Answer

MAF sensors can be located in various places, including being built into the throttle body assembly or mounted on the air cleaner assembly.

Question 4

Technician A says Mass Airflow (MAF) sensors are better sensors than Manifold Absolute Pressure (MAP) sensors for measuring load. Technician B says MAF sensors measure the actual mass of the air coming into the engine, so the Powertrain Control Module (PCM) can accurately calculate the proper amount of fuel. Who is correct?

Accepted Answer

Technician A is correct because MAF sensors provide a direct measurement of the air entering the engine, which can be more accurate for load measurement. Technician B is correct because MAF sensors measure the actual mass of air, allowing the PCM to calculate the correct fuel amount.

Question 5

Technician A says sometimes Mass Airflow (MAF) sensors can be cleaned when they have a buildup of dirt and contamination. Technician B says some manufacturers specifically say not to clean their MAF sensors. Who is correct?

Accepted Answer

Technician A is correct because some MAF sensors can be cleaned to remove dirt and contamination. Technician B is also correct because some manufacturers advise against cleaning MAF sensors and recommend replacement instead.

Question 6

Since 1996, the __________ is the primary sensor for determining an engine's load.

Accepted Answer

The Mass Air Flow (MAF) sensor is primarily used to determine the engine's load by measuring the amount of air entering the engine.

Question 7

Technician A says that the MAF sensor measures the mass of the incoming air. Technician B says that a MAF is used because the more air entering the engine means the harder an engine is working. Who is correct?

Accepted Answer

Technician A is correct because the MAF (Mass Air Flow) sensor measures the mass of the incoming air to the engine. Technician B is also correct because the MAF sensor helps determine the engine load by measuring the amount of air entering the engine, which correlates with how hard the engine is working.

Question 8

Technician A says that any air leaking after the MAF will cause an inaccurate reading that may cause a transmission to have early shifting and driveability problems. Technician B says that any dirt on the MAF will not cause an early shifting problem and driveability problems. Who is correct?

Accepted Answer

Technician A is correct because any air leaking after the Mass Air Flow (MAF) sensor can cause inaccurate readings, leading to incorrect air-fuel mixture calculations, which can affect engine performance and transmission shifting.

Question 9

All MAF sensors can be safely cleaned.

Accepted Answer

Not all MAF (Mass Air Flow) sensors can be safely cleaned; some are sensitive and can be damaged by cleaning, especially if they have delicate components or coatings.

Question 10

Technician A says that a MAF sensor that is not reading correctly may be dirty and need to be cleaned. Technician B says that a MAF sensor that is not reading correctly may be dirty and can only be replaced. Who is correct?

Accepted Answer

The answer of Technician A says that a MAF sensor...

Question 11

MAP sensors may be used to test if certain emissions-related components are functioning properly, as some emissions components will cause changes in manifold pressure as they operate.

Accepted Answer

MAP sensors measure manifold pressure, which can be affected by emissions-related components, allowing for testing of their functionality.

Question 12

Technician A says the engine load sensor is used to determine when the Torque Converter Clutch (TCC should be applied and released). Technician B says Manifold Absolute Pressure (MAP) sensors may be used to test certain emissions related components for proper function. Who is correct?

Accepted Answer

Technician A is correct because the engine load sensor can influence TCC application and release. Technician B is correct because MAP sensors can be used to monitor emissions-related components.

Question 13

Technician A says a typical Manifold Absolute Pressure (MAP) sensor can be connected directly to the intake manifold or connected through a vacuum hose. Technician B says most modern MAP sensors do not use a flexible silicon chip within a chamber anymore. Who is correct?

Accepted Answer

The answer of Technician A says a typical Manifold Absolute...

Question 14

Which of the following is used on electronically controlled automatic transmissions in place of the vacuum modulator valve?

Accepted Answer

The Manifold Absolute Pressure (MAP) sensor is used in electronically controlled automatic transmissions to measure engine load, which replaces the function of the vacuum modulator valve in older systems.

Question 15

Technician A says Manifold Absolute Pressure (MAP) sensors can be connected directly to the intake manifold or connected through a vacuum hose. Technician B says most modern MAP sensors have replaced throttle position sensors. Who is correct?

Accepted Answer

MAP sensors can be connected directly to the intake manifold or connected through a vacuum hose.

Question 16

Manifold vacuum is a good indicator of engine load and was used on hydraulically controlled transmissions through the vacuum modulator.

Accepted Answer

Manifold vacuum reflects engine load and was historically used in hydraulic transmissions to adjust shift points via a vacuum modulator.

Question 17

The sensor responsible for sending a signal that indicates the amount of load on an engine is the:

Accepted Answer

The MAP (Manifold Absolute Pressure) sensor measures the pressure in the intake manifold, which is an indication of the load on the engine.

Question 18

Technician A says that the TCC cannot transmit torque very well without slipping when an engine is under load. Technician B says that the MAP sensor is used by the PCM/TCM to prevent TCC clutch lockup when under a load. Who is correct?

Accepted Answer

The TCC cannot transmit torque very well without slipping when an engine is under load, and the MAP sensor is used by the PCM/TCM to prevent TCC clutch lockup when under a load.

Question 19

After 1996, the MAP sensor became the primary sensor to determine engine load.

Accepted Answer

The Mass Air Flow (MAF) sensor, not the MAP sensor, became the primary sensor for determining engine load in many vehicles after 1996.

Question 20

Technician A says that when a vehicle is determined to be under a light load, the PCM will not have the transmission will not delay the shifts. Technician B says that when a heavy load is determined from the MAP sensor, the PCM delays the transmission shifts. Who is correct?

Accepted Answer

Both technicians are correct. Under a light load, the PCM does not delay shifts, and under a heavy load, detected by the MAP sensor, the PCM delays shifts to optimize performance.

Quiz 11: Electronically Controlled Transmission