My car won't crank
 

I have a 2003 Mazda 6s. When I try to start the engine. It won't start and there is no sound at all. And the light shows on the panel. It seems the car just got the power from the battery, but it cannot start the engine. This morning I started it again. And the check engine light is on. I checked the code in a store. It is U0100. It says" Lost communication with engine control module/power train control module "A" ". This afternoon I tried to start it again. It won't crank again. Any idea what it could be.

Lost Comm code is bad. You may have to pay a visit to your closest Mazda Dealer.

-Sheldon.