2006 Kia Sedona carnival runing without ignotion key

Hi, I have 2006 kia carnival 2.7 liter, I have concern with turn the motor off, start ok as normal , but i can't switch off motor. when switch off all dash lights off like normal, when key on all ok inculding rev meter. also i notice car have only limited throtall responce, key off no throtall atall. To switch off car i have to pull the main relay at engine bay.
test carried out ignition,immobolizer, ect..
If any one have any idea please let me know . thanks .....