WHILE DRIVING VEHICLE BEGAN TO SMOKE FROM ENGINE COMPARTMENT, NOISE CAME FROM ENGINE COMPARTMENT, VEHICLE SIGNIFICANTLY LOST POWER. DRIVER COULD NOT SHUT OFF ENGINE....STARTER WAS TRYING TO CRANK ENGINE-EVEN WHEN IGNITION WAS IN SHUT OFF POSITION. ENGINE SUDDENLY DID NOT HAVE FULL POWER. SMOKE AND BURNING SMELL CONTINUED TO INCREASE FROM ENGINE COMPARTMENT WITH NO WAY TO SHUT OFF ENGINE. GM RELAY #12193614 WAS REPLACED, AS WELL AS BURNT OUT STARTER. RELAY IS AVAILABLE TO NHTSA. GM WAS NOT INTERESTED ACCESSING PART WHEN OFFERED TO THEM. *TR