The Department for Transport (DfT) will carry out tests on the Jeep, as it did after the Volkswagen emissions scandal broke.
A DfT spokesman said: “We are pressing Fiat Chrysler UK for more information about emissions from the 3700 Jeep Grand Cherokee cars that have been registered in the UK.
“Our priority is to protect UK consumers and we have instructed our Market Surveillance Unit to undertake testing on one of these vehicles at the earliest opportunity.”
A total of 4235 Jeep Grand Cherokees could be implicated, according to the Society for Motor Manufacturers and Traders (SMMT), although it hasn't yet been confirmed if the software with which the EPA has taken issue features on all versions of FCA's 3.0-litre V6 diesel engine, including those sold in the UK. Models thought to be affected were built between 2014 and 2016.