Error saying my key could not communicate with the engine compound

My car's security light came on several months ago. When you turn the key into the "off position, the cars system wouldn't shut down, and therefore running the battery dead. My manual told me a way to bypass this, by hitting a switch or button, located in the steering column. I did this for about a month, and car wouldn't start one day. With the Battery charged, it wouldn't start, attempt to turn over or even click. Had it took to a shop and put on computer. After resetting the security lock, it had an Error saying my key could not communicate with the engine compound? What can i do