Transmission Issue Saturn L100

I currently drive a 2002 Saturn L100. This past week when driving down a large bluff, the engine suddenly stopped accelerating. The speedometer needle started dropping and I could not accelerate, the engine light started flashing but the engine never stopped running. I pulled over to the side of the interstate at the bottom of the hill and the engine light shut off. I then tried to accelerate again and all was fine. This has happens twice since then and it always happens driving downhill and when I get to the bottom it's fine again. Is this a transmission problem? Any ideas as to what is occurring?