Germany's Federal Motor Transport Authority (KBA) has approved Volkswagen's proposed modification of around 1.1m more VW, VW commercial and Audi brand models.

Owners of VW Tiguan and Caddy models with EA189 two-litre TDI diesel engines are now being informed and arranging dealer service bookings, VW announced recently. KBA has now approved over 2.5m VW group vehicles for the modification.

Modifications for several 2.0 TDI variants used in Golf, Passat and Tiguan models have been approved and Audi has the green light to call back A4, A5, A6 and Q5 vehicles with the same engines. SEAT Exeo recalls are already under way.

All of the affected group brands' partner businesses are prepared in both organisational and technical terms for carrying out the required software update. Trained service staff are at the customers' disposal to make appointments and answer any questions related to the service process.

Vehicles sold in the US and Canada will be subject to separate recall programmes once modifications are approved by local regulators. Modifications in the remaining markets are dependent on official decree in each individual country.

In Germany, customers are being informed in a two-stage process: a first letter tells owners their vehicles are affected by the recall and, following KBA approval of repair details, a second invites them to make service bookings. The programme is being rolled out in phases to avoid overloading dealers and the repair parts supply chain.

For 1.1m vehicles already approved for modification, the KBA has confirmed there is no change to fuel consumption, performance or noise emissions following the software update.