ADT Electrical Systems & Wiring 2

Question 1

Which CAN bus network in Audi vehicles is primarily responsible for connecting the engine control module (ECM) and transmission control module (TCM)?

Accepted Answer

Powertrain CAN

Answer

The Powertrain CAN bus connects drivetrain-related control modules such as the ECM and TCM for high-speed data exchange.

Question 2

When measuring voltage drop across a ground connection in an Audi, what is the maximum acceptable voltage drop?

Accepted Answer

0.1V

Answer

A voltage drop greater than 0.1V across a ground connection indicates excessive resistance that can cause electrical faults.

Question 3

What does a 'high resistance' fault in a wiring harness typically cause on an oscilloscope signal trace?

Accepted Answer

Signal amplitude decreases or signal is distorted

Answer

High resistance in a circuit reduces current flow, causing voltage amplitude to drop or the signal waveform to become distorted.

Question 4

In Audi's FlexRay communication system, what is the primary advantage over CAN bus?

Accepted Answer

Higher data transfer rate and deterministic timing

Answer

FlexRay offers up to 10 Mbps data transfer with deterministic timing, making it suitable for safety-critical systems like active suspension.

Question 5

A customer reports intermittent electrical faults that only occur when the vehicle is cold. The MOST likely cause is:

Accepted Answer

Thermal contraction causing a cracked solder joint or loose connector

Answer

Cold temperatures cause metal contraction, which can open cracked solder joints or loosen connectors, creating intermittent open circuits.

(ADT) Audi Diagnostic Technician Practice Test