I have a 95 grand cherokee limited (ZJ?) with a no start problem. I took it to the Dealership for an EXPERT diagnosis. They said the PCM was bad...the could hear it rattling with broken pieces inside. Problem is, nothing had been disturbed. It had never been removed from the firewall to be "Rattled" and I've lost faith in the diagnosis. How can I confirm that it's bad? Any testing methods a novice can do? I'm not inept, just under educated. Any help in the right direction is very appreciated. Thanks in advance for your time and knowledge. Ed

 

"how do you know when your PCM is bad?"

code 53 is a good start.

 

I thought the PCM was potted on the inside? No rattle.

Hook your own scanner up to it and see what you get. If you get a 53 (or P0601), its toast. Here. > P0601