I have this code PO690 showing up right after the install. I love the new tune by the way! The guy scanning told me it was a ignition/voltage issue? If I disconnect the battery is goes away for the first start up and then comes back. I can't find this code anywhere on the charts. I dropped Nelson an email. Any suggestions? I had to repost because I posted one to many #'s in the code.

 

ECM/PCM Power Relay Sense Circuit High is the code. I thought it was gonna be a battery code when you upgrade the 2000 to a 2002 pcm. What year is it your truck?

 

It's a 2008.

 

Found the problem. One pin on the PCM was bent while putting in. Straightened the pin, reinstalled PCM, no more SES.