2005 Jaguar XJ8. The air bag suspension light illuminated. While driving approximately 70 mph, the suspension lowered without warning, which was a safety concern while the vehicle was in motion. The vehicle was taken to an independent mechanic for inspection and diagnostic testing. The failure mileage is not available. The air suspension suddenly deflated while driving, this is an ongoing issue that makes the vehicle difficult to steer and brake. If the vehicle sits to long (over night) the loss of air is significant, and the vehicle has to run for several minutes to allow the compressor to inflate the system. In order to reset the fault the vehicle has to be stopped, turned off and restarted in order to reset the system. The fault light comes on and the vehicle gets so low that it becomes hard to control, and occasionally on bumpy roads the front wheels rub inside of the wheel well.