Jenn-Air ovens, like all self-cleaning ovens, heat to extremely high temperatures when the self-clean mode it on. This burns any food ash, thus cleaning the oven. However, the self-cleaning process does not clean overly abundant spills in the oven -- they can cause fire if they aren't removed before the process starts.
Remove all of the broiler pans and any other pans you store in the broiler area from the Jenn-Air oven.
Wet a cloth and wipe down the front of oven and the door, the porcelain lining and the oven door frame. Wipe any excess spills out of the oven. Remove the oven racks from the inside of the oven.
Close the oven door and select "Clean Pad." Choose the amount of time you want the self clean to run and press "Stop Time Pad." Select the time you want the self clean to stop.
Fill the sink with warm soapy water and scrub the broiler plate and oven racks until clean. Set them out to dry.
Open the oven when the self-cleaning cycle is finished and the door unlocks. Replace the oven racks and broiler plate. Wipe up any ash left over from the self-clean process.