AUDI AUDI Engine Management & Fuel Systems 2

Question 1

Which component on an Audi 2.0 TFSI engine drives the high-pressure fuel pump?

Accepted Answer

A dedicated lobe on the intake camshaft

Answer

The HPFP on the 2.0 TFSI is driven by a three-lobe cam on the intake camshaft, which reciprocates the pump plunger to generate high injection pressure.

Question 2

What is the purpose of the Audi exhaust gas recirculation (EGR) system?

Accepted Answer

Reduce NOx emissions by diluting the intake charge with inert exhaust gas

Answer

EGR lowers peak combustion temperatures by introducing exhaust gas into the intake, which reduces the formation of nitrogen oxides (NOx).

Question 3

On an Audi with a turbocharged engine, what is the function of the diverter valve (DV)?

Accepted Answer

Recirculates compressed air back to the turbo inlet when the throttle closes to prevent compressor surge

Answer

The diverter valve (also called blow-off or bypass valve) vents compressed air back to the turbo inlet when the throttle closes suddenly, protecting the turbocharger from surge.

Question 4

When an Audi oxygen sensor reads a fixed voltage of approximately 0.45V and does not switch, what does this typically indicate?

Accepted Answer

The sensor is lazy or failed and not responding to exhaust gas changes

Answer

A healthy narrowband O2 sensor should oscillate between approximately 0.1V and 0.9V; a fixed mid-range voltage indicates a lazy or dead sensor that is no longer reacting to exhaust gas.

Question 5

What Audi fuel system component regulates low-side fuel pressure supplied to the high-pressure pump?

Accepted Answer

In-tank low-pressure fuel pump module

Answer

The in-tank low-pressure fuel pump delivers fuel to the HPFP at a regulated low-side pressure, ensuring the high-pressure pump has adequate supply under all conditions.

(AUDI) Audi Certified Mechanic Practice Test

(AUDI) Audi Certified Mechanic Practice Test

AUDI AUDI Engine Management & Fuel Systems 2