Originally Posted by Mikaere808
I was also told because the battery died that it reset the ECU. And that I need to drive it for awhile at 55mph or above to get the ECU working again. Is that true? Hopefully that's true cause that will be a much cheaper fix than taking it to a shop.
Nothing to do with the battery, you may need to drive it to get readiness codes but the scanner should still work.
Do you have an aftermarket radio?
There's a problem with some harnesses shorting the K-line to 12 volt. It will block communications.
The other common failures that block the K-line are the cluster, ABS module and comfort / alarm module. Unplug them one at a time to find the culprit.