Fiat Chrysler is recalling 4.8 million vehicles in the U.S. because in rare but terrifying circumstances, drivers may not be able to turn off the cruise control.

The company is warning owners not to use cruise control until the cars, SUVs and trucks can be fixed with a software update.

Fiat Chrysler says the condition can occur if the cruise control accelerates at the same time an electrical short-circuit happens. But the brakes are designed to overpower the engine and the vehicles could still be stopped. Shifting into park would cancel the cruise, but tapping the brakes or turning off the cruise control button won’t work.

The problem was found in testing of the vehicles’ computer network. FCA says it has no reports of crashes or injuries. After the testing uncovered the trouble, FCA said it reviewed customer complaints and found only one that may be related.

The recall includes 15 Jeep, Dodge, Chrysler and Ram models from six model years with gasoline engines and automatic transmissions.

Models in Canada, Mexico and other countries also are affected, but the company is still sorting out which ones.

(AP)