ADT Emissions Control & Environmental Compliance 3

Question 1

An Audi Q7 3.0 TDI (EA897) enters limp mode after the AdBlue tank runs empty. How is full power restored after refilling?

Accepted Answer

Reset the SCR adaptation via VCDS/OBD and clear codes after confirming fluid level

Answer

After AdBlue refill, the SCR adaptation must be reset through diagnostic software and faults cleared before the ECU exits the power-reduction strategy.

Question 2

What does a negative fuel trim (LTFT) value at idle combined with a rich lambda reading typically indicate regarding emissions compliance?

Accepted Answer

Rich mixture causing elevated CO and HC emissions at the tailpipe

Answer

Negative LTFT means the ECU is subtracting fuel to compensate for a rich condition, and if trims are saturated, excess CO and HC will pass through the catalyst.

Question 3

During OBD II readiness monitor testing for an Audi, the oxygen sensor monitor shows 'not ready.' What driving cycle is most likely required to set it?

Accepted Answer

A standard warm-up cycle with steady-state cruise then deceleration fuel cut-off

Answer

The O2 sensor monitor requires a warm engine, steady cruise to establish closed-loop, and deceleration fuel cut-off to test the sensor's lean response.

Question 4

What is the legally mandated maximum allowable venting of HFC-134a refrigerant during Audi A/C service under EPA Section 609?

Accepted Answer

No venting is permitted; all refrigerant must be recovered

Answer

EPA Section 609 prohibits all intentional venting of refrigerants with global warming potential; technicians must recover refrigerant before opening any A/C system.

Question 5

An Audi 3.0 TFSI shows P2096 (post-catalyst fuel trim lean, bank 1). Which downstream sensor is providing this reading?

Accepted Answer

Post-catalyst narrowband oxygen sensor (G130)

Answer

The post-catalyst narrowband oxygen sensor (G130) monitors TWC efficiency; a lean signal triggers P2096 if the catalyst is consuming excess oxygen or the sensor is faulty.

(ADT) Audi Diagnostic Technician Practice Test

(ADT) Audi Diagnostic Technician Practice Test

ADT Emissions Control & Environmental Compliance 3