rebuilt 4L60E wont upshift

[Karl Tautfest]

I just rebuilt my tranny and it ran just fine for about 1000 miles. Then it happened again, no 3rd or 4th gear. Originally the 3-4 clutch friction plates were worn out. Now I don't know what the problem is. I took it apart again and the friction plates are good. Any help sure would be appreciated. The tranny is in a 2001 GMC Yukon XL 4X4 with a 5.3L engine Thank you in advance.

 

[Gambles]

When I was in high school I got an alarm put in and when I would remote start it the guy didn't hook a wire up to energize something to the computer, I don't remember for the life of me what it was now.. have you checked all your fuses? My truck only had second gear when it happened to me... 16 mile drive at 35~ down the highway.. lol