Is there a control module that has to be removed before removing the battery? The 4.4 TDV8's engine control module has to at least be lifted out of the way to remove the battery so if the 5.0 has one there too then perhaps the connector has been disturbed.

yes it must be the DME, but i think there is a module which handles the sleep mode of the car. i need to know which one, then i would try to reprogram it