When leaving to return home from out of town trip, all of a sudden the entire dash board went black and the engine decelerated to approx. 5 mph and would not go above this speed. We tried turning off the engine and restarting, but still no dash board and no acceleration. We also tried getting out of vehicle, locking, waiting and then unlocking, restarting with the same result. We called Volvo On Call who had zero information about any technical difficulties and only wanted to call a tow truck to tow our vehicle to another dealership that was 150 miles away from current location and over 300 miles from home. Thankfully, we were able to reach a service person on Saturday at 5:30pm who suggested disconnecting the battery at the negative terminal and leaving it for a couple of minutes and reconnecting. Of course, we had to drive 5 mph to a local WalMart we had spotted during the weekend to buy tools. Another aside is that Volvo On Call couldn't even locate the exact position of our battery in the vehicle. We knew it was in the back, but wasn't sure if it was under tire or on side compartment. After disconnecting the battery for a few minutes and reconnecting, the car was able to start with dashboard and acceleration. Took it to dealership this Monday morning and they didn't acknowledge this was known problem (we searched internet yesterday and found this site) and told them other owners in this same area have experienced the exact same problem. They think it is a software problem, but why didn't they notify all owners to receive a software upgrade on something this serious.