I have a 1997 Dakota the security came on the truck will start and drive. The horn and lights beeps and flickered I bought a new ecm and the lights quit flickering but the security light flashes still and the gauges don't work. How do I fix this

 

Welcome to the forum.

Did you change anything before this happened? The CTM and PCM both are involved in the security system. Sounds like something tripped one of them - not sure how. Unfortunately it can't be reset.