For 05-11, the Fire Suppression System (FSS) was an option offered as a response to the risk caused by high-speed impacts (above 75 MPH) to the rear that caused fuel tank fires from sharp objects stored in the trunk piercing into the fuel tank. The FSS is evidenced by two things - first, the giant red button in the headliner in front of the ticket light, and second, the FSS light in the instrument cluster for 06-11.
The FSS can be deployed by hitting the clear plastic cover with significant force while the key is in the ignition or by removing the cover (either pushing to unlatch or pulling) and pushing the red button. It is critically important that you do not push the FSS button except in the event of a serious crash that causes or is likely to cause a fire. When the FSS activates, it drops down sprayers that spray fire retardant liquid around the area under the fuel tank. Once deployed, the vehicle should not be driven because of the deployed nozzles, and the FSS must be removed or replaced. The liquid is non-toxic and does not damage the vehicle, but the deployment is achieved through a gas-generation system similar to an airbag, so it cannot be reset.
The system deploys rather explosively, as seen here.
It was possible to install the FSS at a dealer as an aftermarket option, although many dealers will no longer do so. It is not possible to disable the FSS itself through Forscan, although the light can be toggled.
Note that the FSS is not the same as the “FIRE Panel”, which was an aftermarket shroud fitted onto the fuel tank that disperses a fire-retardant powder when impacted. The FIRE Panel cannot be manually “activated”, so it cannot be identified without visually inspecting the fuel tank.