310S Fuel and Emission Systems 5

Question 1

What is the purpose of the fuel pump driver module in modern vehicles?

Accepted Answer

To control fuel pump speed based on engine demand, improving efficiency and reducing noise

Answer

To boost fuel pressure beyond the regulator setting

Answer

To filter electrical noise from the fuel pump circuit

Answer

To monitor fuel level for the gauge

Question 2

What is the function of the intake air temperature (IAT) sensor?

Accepted Answer

To provide air temperature data to the ECM for adjusting fuel delivery and ignition timing based on air density

Answer

To control the electric cooling fan

Answer

To regulate the cabin air conditioning system

Answer

To measure exhaust gas temperature

Question 3

A four-gas exhaust analyzer shows high CO and high HC readings. What condition does this indicate?

Accepted Answer

A rich fuel mixture with incomplete combustion

Answer

A lean fuel mixture

Answer

An efficient catalytic converter

Answer

Normal exhaust emissions at idle

Question 4

What is the function of the selective catalytic reduction (SCR) system in diesel vehicles?

Accepted Answer

To inject diesel exhaust fluid (DEF/urea) into the exhaust to chemically reduce NOx emissions

Answer

To filter particulate matter from exhaust gases

Answer

To recirculate exhaust gases into the intake manifold

Answer

To regenerate the diesel particulate filter

Question 5

What is the primary cause of a lean misfire at idle?

Accepted Answer

An intake manifold vacuum leak allowing unmetered air to enter

Answer

Excessive fuel injector flow

Answer

A restricted exhaust system

Answer

An overly advanced ignition timing setting

Question 6

How does the ECM detect a misfire?

Accepted Answer

By monitoring crankshaft speed variations through the crankshaft position sensor

Answer

By monitoring exhaust oxygen sensor voltage changes

Answer

By measuring cylinder compression through the MAP sensor

Answer

By detecting vibration through the knock sensor