In a submission to Germany's Federal Motor Transport Authority, Volkswagen has outlined how it plans to fix two of the EA189 turbo-diesel engines equipped with emissions testing defeat devices.
For the 1.6-litre version of the EA189 TDI engine, Volkswagen is planning to fit a flow transformer upstream from the air mass sensor. Volkswagen says that the transformer "calms the swirled air flow in front of the air mass sensor and will thus decisively improve the measuring accuracy of the air mass sensor".
Air mass throughput is said to be a "very important parameter for the engine management for an optimum combustion process". Dealership personnel will also update the engine's control software.
All up, the company estimates the fix will take around an hour to implement.
For the 2.0-litre EA189 turbo-diesel, the German automaker is proposing a software upgrade to rectify its current problems. This change, it says, will take under 30 minutes for dealers to apply.
"Thanks to advances in engine development and improved simulation of currents inside complex air intake systems, in combination with software optimisation geared towards this, it has been possible to produce a relatively simple and customer-friendly measure," Volkswagen said in its submission.
"The objective for the development of the technical measures is still to achieve the applicable emission targets in each case without any adverse effects on the engine output, fuel consumption and performance. However, as all model variants first have to be measured, the achievement of these targets cannot yet be finally confirmed."
Assuming Volkswagen's proposed changes are accepted by the German authorities, the automaker plans on implementing these fixes from January 2016.
The company hopes to minimise the impact on customers as it seeks to roll out the updates. As such, it will "contact all customers and endeavour to consider individual customer needs during the implementation of these measures to avoid any disadvantages for the customer such as possible curbing of their mobility" and will "thus ensure that all customers are offered appropriate replacement mobility options free of charge".
Owners of affected vehicles will have until December 31, 2016 to have their cars upgraded and fixed, as Volkswagen is "expressly forgoing the right to plea on the grounds of statutes of limitations in respect of any warranty or guarantee claims due to the software installed in vehicles with EA 189 engines, as long as the rights to make any such claims have not already expired".
Volkswagen is currently working on a solution for its 1.2-litre three-cylinder turbo-diesel engine. The carmaker believes that a solution will be detailed by the end of the month, and that the only changes required will be to the motor's software.
It should be noted at this point that the fixes detailed here are purely for the European market. The company may need to institute more extensive fixes in the US where just under half-a-million Audi and Volkswagen cars were sold with the affected 2.0-litre EA189 engine.
CarAdvice has contacted Volkswagen Australia for comment on how this latest development will play out in our market.
More: Read all of CarAdvice's "dieselgate" articles.