No details have been released by the Kraftfahrt-Bundesamt (KBA), but it is alleged that the defeat device switched off a filter after 90 minutes – just over an hour after the 20-minute emissions test procedure ended.
Fiat has been targeted with accusations of cheating since the Volkswagen dieselgate emissions scandal broke: this is the second round of accusations aimed at Fiat Chrysler Automobiles (FCA) by the KBA in a year, with a previous accusation alleging that a different defeat device was in use.
An FCA spokesman said: "In response to the publication by Der Spiegel of rumours about KBA emissions tests and leaked internal KBA documents regarding the 500X, we can only reiterate that we believe that the 500X conforms to all applicable emissions requirements, a fact that has been verified and reconfirmed by the Italian Ministry of Transport."
The KBA's first accusation
A senior FCA executive has denied accusations that the company employed a cheat device to circumvent emissions tests.
Chief technical officer Harald Wester defended the firm against claims from German authorities that a diesel Fiat 500X used unauthorised software during emissions testing. The KBA made the accusation last May, saying the car’s engine management software switched off its exhaust treatment systems after 22 minutes, thus allowing it to pass Germany’s standard type approval test, which takes around 20 minutes to complete.
At a meeting of a European Parliament inquiry committee into emission measurements in the automotive sector (EMIS), Wester said he could not comment on the details as the matter is subject to mediation and litigation, but added: “The 500X meets the relevant Euro 6 limit in the regulatory NEDC test and does not detect that it is being tested.
“Contrary to allegations, the 500X does not deactivate its emission control system, but uses control strategies that modulate the emissions control system solely to protect the integrity of the engine and the safety of the vehicle occupants in accordance with applicable regulations.”
However, EMIS members asked for more details and challenged Wester on technical and legal definitions around his justification of such a modulation system.
Wester was also questioned about French tests that showed emissions up to 15 times greater than those claimed. He said he would need more data about test conditions to explain this.
The European parliamentary enquiry was set up in the wake of the Volkswagen dieselgate scandal and has been hearing from academic institutes, trade associations and non-governmental organisations since March.