Fiat Chrysler is recalling 4.8 million US vehicles over a defect that could prevent drivers from turning off cruise control.

It warned owners, including those outside the US, not to use the function until they get software upgrades.

The Italian-American car maker said no injuries or crashes were related to the large recall campaign.

But it had one report of a driver of a 2017 Dodge Journey being unable to turn cruise control off.

The firm said an "unlikely sequence of events" could lead to drivers being unable to cancel cruise control.

Fiat Chrysler said drivers could still stop their car by continuously putting on the brakes or by shifting into neutral gear and braking.

Most of the vehicles being recalled cover models built between 2014-2018. Some markets outside the US, including Canada and Mexico, are also affected, but the total number of vehicles involved globally is not known.

The firm said it planned to contact affected customers.

Among the vehicles being recalled are the Chrysler 200, Chrysler 300, Chrysler Pacifica, Dodge Charger, Dodge Challenger, Dodge Journey, Dodge Durango, Jeep Cherokee, Jeep Grand Cherokee, Jeep Wrangler and Ram 1500, 2500 and 3500 pickup trucks and Ram 3500/4500/5500 cab trucks.

Some markets outside the US and Canada are also recalling certain Fiat Fremont models.

The problem

Fiat Chrysler said that at times its cruise control systems automatically start accelerating to help cars keep at the same speed, such as when going up a hill.

If that automatic acceleration happens at the same time as a short-circuit in the car's electrical system, a driver could be unable to switch off cruise control.

Fiat Chrysler said vehicles may be put in "park" once stopped, which turns cruise control off.

The carmaker, which in 2015 was hit with penalties from US regulators totalling $175m (£131m) for safety lapses, did not say how much the recalls would cost.