Faulty software could cause the cruise control system to lock or speed up without warning.

Fiat Chrysler Automobiles (FCA) has recalled the Chrysler 300 and Jeep Grand Cherokee over concerns faulty software could cause the cruise control function to lock or unexpectedly accelerate.

The manufacturer reports affected vehicles could feature a fault in the Power Control Module (PCM) software, which may affect the cruise control system.

If the condition occurs, the vehicle speed could lock when cruise is engaged, or unexpected acceleration may occur.

FCA says if the driver doesn't shift to neutral or apply the brakes to stop the vehicle, the fault poses an accident risk.

Affected 'LX' Chrysler 300 and 'WK' Jeep Grand Cherokee vehicles were sold from 2014 through to 2018. The VIN list for the recalled 300s can be viewed here, and the list for the Grand Cherokees here.

Owners of these units will be contacted by FCA Australia via mail, and advised to schedule and appointment with their local dealer.

During the appointment, the vehicle's software will be inspected, and reprogrammed if necessary.

This latest notice comes after the smaller Jeep Cherokee was recalled for the same issue last month.

For more information, contact 1300 133 079.