Emergency Management Command Vehicle was a mobile command vehicle designed for commanding response teams for natural disasters.
Assassination of Ukkon
After the Hammer of Dawn Strikes, Gabriel Diaz and Sid Redburn returned to the Motor Pool in the Aldair Army Base to regroup with the stationed Sappers. Unfortunately, they were massacred by the Locust Horde, forcing the two to take refuge inside a truck, which seemed to resemble the description and role of the Emergency Management Command Vehicle. This truck would then be turned into a mobile HQ for Diaz's squad in their mission to assassinate Ukkon. 
Behind the Scenes
- It is unknown if the truck used by Gabriel Diaz was a Emergency Management Command Vehicle or a CIC Truck. Seeing as how a CIC Truck is just a name for any vehicle that has been turned into the HQ for the Coalition High Command specifically and that the Emergency Management Command Vehicle is a command vehicle for the COG's equivalent of the National Guard in times of disaster, the evidence points to the latter being the case.