Transmission Problem?
Climbed over the southern Rockies in extreme heat the other day on I8 and in to San Diego. Tranny overheated and went in to fail safe on that long eastern climb, even though the engine temp was OK or ...
Forum Discussion
Daveinet wrote:
A couple of things happen in fail safe mode. The ECM runs the pump pressure wide open to prevent slip. That also increase the TC lockup pressure to max, to prevent slip. Once this happens, the ECM remembers this condition and maybe assuming that the pump pressure needs to be operated higher from now on. If that is the case, it should eventually figure out everything is OK and go back to normal. I would change the fluid (especially if it smells burnt), maybe reset the ECM, and see if things settle down. I realize you are out on the trip, but I think it is worth it, to change the fluid.
Here is a couple of articles that tell you a little about how it works, and how the ECM is programed to think:
http://www.motor.com/article.asp?article_ID=1039
http://forum.efilive.com/showthread.php?4305-4L80E-Reference-Material
Great info and a good tech explanation. The fluid looks good and smells good, but new can't hurt or can it, as I've heard of problems with changing, unless it's always been done regularly and I have no history on this rig that we bought in 07? As for resetting the ECM, I thought that as soon as I began to read your excellent post. Now, what is the best way to do that and can I just disconnect the chassis battery for a few minutes to accomplish the same thing?
