My check engine light came on so I hooked up my AutoXray scan reader to pull the codes. Scanner says it's unable to read...So I pulled out the ole paper clip and jumped A and B in the ALDL....Interesting that I get NO blinking from the light at all..Any solutions out there on why ?

 

If you verify the ecm power b1, c16, a6 and ground behind the passenger side cylinder head and you don't have communication with the ecm sounds like a bad ecm.

 

That's what I was thinking..But it starts and idles fine, drives fine...It all started when the fans would turn on as soon as I turned the ignition key to the on position. And of coarse the SES light comes on. Interesting the security light goes out right away. I put a pcm4less performance chip in a year ago. All was fine up to just recently when I got the dreaded SES light.