The newly launched Mazda6 is the subject of a recall affecting 502 diesel models and 165ps Sport petrol models in the UK and up to 15,000 cars globally.
The recall is "a precautionary measure", said Mazda.
The recall will deal with a potential fault with a component in the DC/DC convertor that is located under the front passenger seat. The component is there to suppress electrical interference with the radio.
The convertor will be replaced free of charge.
A Mazda spokesman said: "The likelihood of there being a fault is very small so this recall is a precautionary measure. But where there is a fault it may cause overheating of the unit and in a worst case scenario, a fire may result.
"For all customers who are awaiting delivery of their new Mazda6 these cars will have the modification made before delivery which, in the short term, may result in a slight delay. All customers will be contacted by their dealer to update on the expected delivery date."