Updating the thread:
I pulled both the TCU and ECU out of the van and brought them to work (hi-tech device engineering co). I asked one of our electrical engineers to inspect the printed circuit boards.? They found nothing wrong, all the solder joints were good, no voids, cracks, corrosion.? I did get a bit more aggressive in cleaning the pins.? After re-install, I was still in limp mode.
I decided to take the van on a trip anyway, shifting manually and going slow on the highway.? As I mentioned previously, it will often fix itself randomly along the road.? 1 hour into the drive, that's exactly what happened - into overdrive she goes - Life is Great!? Except I have no idea why it keeps doing this, and I'm certain it will fail again before long.
Once again, the instrument panel went haywire briefly, immediately before the tranny came out of limp mode.? I should mention that when this epilepsy occurs, my digital clock resets to 1PM and the trip odometer clears itself back to 0.0.? Strange...
I'll keep trying to find the problem and will update again.? Thanks.
