Tranny problems when A/C is on

[synthetic-oil]

Had the 4L80E rebuilt. Now if the A/C is on I get a 85 & 87 code but not when it is cold, only after it gets hot. With the A/C off if runs and shifts fine no problems. Anyone got any ideals?

Jeff

[grancito]

If you don't get any suggestions, try searching for temperature related transmission problems/codes, it could be something like the temp sensor on the thermostat housing, I guess you have a 94 or 95, fill in your "signature on your home page with the vehicle details so we have more info.

[synthetic-oil]

Before I went and took the truck away from the idiots that did the tranny work they installed an ECM, ignition switch, all electronics in the trany, all the temp sensors, VSS, and VSS buffer. At least I didn't have to pay for any of it.
It ran and shifted fine before it went in to the shop.