Volkswagen engineers have determined that the air sensor, between the filter and the intake manifold, was not correctly registering the mass of air it was sucking in, due to the formation of turbulence. To eliminate this turbulence, a small filter will be installed, which will increase the accuracy of the sensor. In addition, the control unit software will be updated. With better control of combustion, the emission of nitrogen oxides (NOx) will be reduced.
The modification will take just under an hour. According to the manufacturer, the aim is that there will be "no adverse effects on fuel consumption or performance", although they have not specified this in figures. Nor have they said that there will be no real loss of performance or a slight increase in fuel consumption. This solution is certainly cheaper than replacing catalytic converters or installing urea injection systems.
Volkswagen cannot yet be sure that the design goal will be achieved, as measurements are still needed. For some models, the solution will take months.
For the 2.0 TDI engines, an update of the control unit will suffice, an operation that will take half an hour. For the 1.2 TDI engines, the solution will be known at the end of the month, although everything suggests that a simple update of the control unit will suffice. What will this modification consist of? Surely there will be a richer injection map to increase the combustion temperature, and therefore the NOx catalytic converters more effectively neutralize these gases. This would imply a slight increase in diesel consumption.
To minimize inconvenience to customers, Volkswagen is committed to providing mobility solutions for each individual case, free of charge. When we talk about Volkswagen, we are also talking about the Audi, SEAT and Skoda brands. For warranty purposes, no customer will be disadvantaged by the wait.