ADT Powertrain & Engine Management Systems 5

Question 1

An Audi A5 2.0 TFSI exhibits hesitation on cold starts only, disappearing once fully warm. Long-term fuel trims are near zero. Which component is MOST suspect?

Accepted Answer

High-pressure fuel pump cam follower wear causing low cold start rail pressure

Answer

HPFP cam follower wear is a well-documented EA888 issue where cold oil viscosity allows the follower to pump insufficiently, causing low rail pressure only during cold start.

Question 2

On an Audi multitronic (CVT) transmission, what does the variator's hydraulic pressure control directly affect?

Accepted Answer

Clamping force on the drive and driven pulleys determining gear ratio and torque capacity

Answer

The variator's hydraulic pressure controls clamping force on both primary and secondary conical pulleys, which simultaneously sets the gear ratio and the belt's torque-transmitting capacity.

Question 3

A technician finds a stored P2187 (System Too Lean at Idle, Bank 1) with a normal MAF signal and good injector pattern. What is the NEXT logical diagnostic step?

Accepted Answer

Perform a smoke test to locate vacuum or boost tract leaks downstream of the MAF

Answer

If MAF and injector function are normal, an unmetered air leak downstream of the MAF sensor is the most likely lean cause and a smoke test is the most efficient method to find it.

Question 4

When coding a replacement Audi ECM using ODIS, what is the MANDATORY first step before programming the new control module?

Accepted Answer

Record the existing variant coding and adaptation data from the original ECM using ODIS offline data

Answer

Before replacing an ECM, the technician must document all existing variant coding and adaptation values from ODIS to ensure the new module is programmed identically to the vehicle's configuration.

Question 5

On an Audi with a 7-speed S tronic (DL501) transmission, what causes a 'safing' condition where the transmission locks in a single gear?

Accepted Answer

Both conditions can independently trigger a limp/safing mode

Answer

Both TCM loss of ECM communication (CAN timeout) and transmission overtemperature conditions can independently cause the DL501 to enter safing mode to protect the clutch packs.

(ADT) Audi Diagnostic Technician Practice Test

(ADT) Audi Diagnostic Technician Practice Test

ADT Powertrain & Engine Management Systems 5