I've been given an 98 oldsmobile aurora to fix. Here is the problems... Vehicle drives fine for awhile, then after 30-45 mins. of stop and go driving the CEL comes on. The codes that come up are P0753 and P0758, which are codes for electrical problems in both shift solenoids. I can erase them with the scantool but they show back up and the trans. gets stuck in 2nd. If I let sit over night and cool down the codes then take 30-45 mins. of stop and go to show up again. I figured bad solenoids. When I took the trans. pan off I saw that the solenoids had already been updated. I've checked the wire harness that runs thru the trans and found nothing wrong. I'm now looking at the ECM or the alternator as the problem??! Any help would be appreciated!