The plan, which was reported by Autocar in June, is outlined in letters being sent to customers, confirming that it is now being rolled out across the country.
Volkswagen is promising to evaluate potential issues relating to cars that have fewer than 160,000 miles on the clock and have received the fix within the past 24 months.
The letter says that if Volkswagen finds a problem has been caused by the software change, it will “act responsibly and swiftly, in line with its goodwill policy, to respond to the consumers' reasonable concerns”.
This comes despite the brand's claims that the technical fix, which has been rolled out to more than 4.7 million Volkswagen Group cars worldwide in the wake of the Dieselgate emissions scandal, will have no adverse effect on engine running.
A test by Autocar earlier this year revealed that post-fix cars can suffer from worsened fuel economy and increased CO2 output, while a report by the Volkswagen Diesel Customer Forum said that owners of models with the 2.0-litre diesel fix had also experienced breakdowns and mechanical issues.
Volkswagen disputed the findings, stating: “Far fewer than 1% of UK customers who own affected Volkswagen Group vehicles that have received the technical measures have reported any issues.
“That means that more than 99% of customers are satisfied with the application of technical measures, which of course are carried out free of charge. We make it a priority to look at the vehicles of the very small proportion of customers who report any issues.”