ADT Powertrain & Engine Management Systems 3

Question 1

On an Audi 2.0 TDI with a variable-geometry turbocharger (VTG), what actuator controls the position of the variable vanes?

Accepted Answer

Vacuum-operated diaphragm actuator or electric servo motor

Answer

VTG turbochargers on Audi TDI engines use either a vacuum diaphragm or an electric actuator to rotate the variable guide vanes and control boost across the RPM range.

Question 2

An Audi Q7 4.2 FSI shows cylinder-specific misfire codes on cylinders 5 and 6 only. Compression and leakdown tests are within spec. What should be checked NEXT?

Accepted Answer

Injector spray pattern and high-pressure fuel delivery to bank 2

Answer

On bank-specific misfires with good compression, the high-pressure fuel supply circuit (rail pressure, injector function) for that bank should be evaluated next.

Question 3

What is the purpose of the 'Leak Detection Pump' (LDP) in the Audi EVAP system?

Accepted Answer

Pressurize the fuel vapor system to detect small leaks as small as 0.5 mm

Answer

The LDP pressurizes the EVAP system and monitors pressure decay to detect leaks as small as 0.5 mm in diameter, satisfying OBD-II evaporative monitor requirements.

Question 4

During an Audi S4 3.0 TFSI oil consumption test, how many miles must the vehicle be driven before re-checking oil level per Audi's approved procedure?

Accepted Answer

1,000 miles

Answer

Audi's approved oil consumption test requires the vehicle to be driven 1,000 miles under normal operating conditions before rechecking the oil level to determine consumption rate.

Question 5

A fault code P0087 (fuel rail/system pressure too low) is stored on an Audi 1.8 TFSI. After confirming low rail pressure with a gauge, which component should be tested FIRST?

Accepted Answer

Low-pressure fuel pump (LPFP) delivery volume and pressure

Answer

Low rail pressure diagnosis begins with the low-pressure side; insufficient LPFP delivery is the most common root cause and must be confirmed before condemning the HPFP.

(ADT) Audi Diagnostic Technician Practice Test

(ADT) Audi Diagnostic Technician Practice Test

ADT Powertrain & Engine Management Systems 3