A couple minor problems

I have a 1990 Cadillac DeVille. My transmission seema to be very picky when it comes to the outside air temperature. If the temp is below 70 deg. it seems to slip a little and shift hard, but if the temp is above 70 deg. it shifts just fine and I don't notice any slipping, this started after I rearended another car. All the lines for the tranny were still in great shape as well as the cooler. No idea whats going on with it.

Also the last few times I've filled gas I noticed the fuel information center was giving an incorrect reading for the gallons used. I reset that and the avg mpg at every fill. At empty it now says i've used 12 gallons, but when I fill it, it takes a little over 16. I know the fuel is showing the correct fuel level, so it's not an issue with that.

any help would be greatly appreciated.

Welcome to AF, you will need to have a trans tech road test the car and see whats what, no way to accurately diagnose this from here, is the fluid discolored, any recent service done? The bcm is miscalculating fuel usage based on the tank unit readings, again this would have to go thru a complex diagnosis using the on board system, caddyinfo.com has some instructions how to access the system thru the a/c control head.

Thanks for the fast response. I appreciate your help.