The Kia Sedona is well known for presenting issues to the operator when trying to start the engine. This is especially true for vehicles with the Kia smart key. 

An issue with the factory vehicle immobilizer control module can cause the vehicle to think it is being stolen. This will immediately disallow the vehicle from starting. 

Many times, the key is the issue, and vehicles with keyless go or push-to-start technology may function properly if the key is inserted (check owners manual for the location of the port). 

The newest version of the smart key can be used to press the start button, which will allow the vehicle to register the key when the battery is low. 

If these quick tips do not allow the vehicle to start, or the vehicle does not use a smart key, diagnostics will need to be performed by a factory authorized Kia service enter.