2002 x type new transmission issues
I have a 2002 xtype I bought last June with 44,000 miles. I just had a rebuilt transmission and new valve installed last week. It has been running well until I encountered the following sequence of events on the same major intersection today.

So I have a newly rebuilt transmission (cost me $4000) from AAAMCO. Having a 2002 car, my warranty has long expired.

I stop at a traffic light in downtown Los Angeles where I have a steep downward slope (those who are familiar with the intersection of 5th and Grand southbound). The power train light comes on and the engine shakes, and I presume the car goes on limp mode. I find a parking spot and turn off the car. When I turn it back on, no lights appear (no power train light, no check engine light) and the car operates normally again. So I immediately drive it to the AAAMCO shop that rebuilt my transmission. They do a computer diagnostic and nothing shows up. I drove back to work and when I stopped at the same intersection, instead of the power train light appearing before I descend, it appears a few seconds after I finish the descent. So I go limp mode again with the power train light on. I turn it off and after 1 minute, turn it on and no warning lights appear and the car operates normally again.

I have a practically new transmission. My AAAMCO mechanic has checked the bulletins and there is no need for reprogramming and I also checked with a Jaguar dealer and gave them my VIN number, and my car supposedly is not on any transmission recall.

I would apprecite any advice. thanks.