i got a question, i recently had my service engine soon light come on and i tried doing a self diagnostic with the paper clip and it will not flash the codes. a while back it worked and i found my o2 sensor was bad. well now as i turn the key to run the SES light comes on and doesnt flash at all, not even the first 12 code. any ideas on what could be the problem? did i ruin the harness maybe? thanks- 91z28

 

if you have no coeds stored and you jump the ALDL you'll get a code 12 showing the ecm is working properly. no code 12 indicates a problem with the ecm, or maybe a wireing problem between the ALDL and the ecm, or ground.

 

thanks for replying, i appreciate any help i can get. -mike

 

IT BE BETTER IF YOU JUST WENT TWO THE GM DEALER AND BOUGHT A REAL CODE KEY UNSTED OF THE PAPER CLIP. THAT WAY YOU CAN BE SURE THAT THE COMPUTER IS WORKING OR NOT. THE KEY IS ONLY TWO DOLLARS.