AUDI AUDI Engine Management & Fuel Systems

Question 1

What is the primary function of the Audi Motronic engine control module (ECM)?

Accepted Answer

Manages fuel injection, ignition timing, and emission controls

Answer

The Motronic ECM integrates fuel injection, ignition timing, idle control, and emissions management into a single engine management system.

Question 2

On an Audi TFSI engine, what does the 'FSI' component of direct injection mean operationally?

Accepted Answer

Fuel is injected directly into the combustion chamber at high pressure

Answer

FSI (Fuel Stratified Injection) injects fuel directly into the cylinder at pressures up to 200 bar, improving combustion efficiency and reducing fuel consumption.

Question 3

Which Audi engine sensor measures the mass of air entering the engine to calculate fuel delivery?

Accepted Answer

Mass airflow (MAF) sensor

Answer

The MAF sensor measures the actual mass of air entering the intake and provides the ECM with the primary load signal for fuel injection calculations.

Question 4

What condition does a negative long-term fuel trim (LTFT) value indicate on an Audi?

Accepted Answer

The engine is running rich and reducing fuel delivery

Answer

A negative LTFT means the ECM is subtracting fuel because the engine is running rich, indicating excess fuel or a vacuum-related issue.

Question 5

On Audi TFSI engines, what common issue is caused by carbon buildup on the intake valves?

Accepted Answer

Rough idle, misfires, and reduced power due to restricted airflow past valves

Answer

Because direct injection bypasses the intake valves, oil vapors from the PCV system deposit carbon on valve stems and seats, restricting airflow over time.

(AUDI) Audi Certified Mechanic Practice Test

(AUDI) Audi Certified Mechanic Practice Test

AUDI AUDI Engine Management & Fuel Systems