Chevrolet Repair: 94 Suburban Trans., pressure gage, test sequences

Question
I have a 94 Suburban w/ 5.7 and 4L60E. I have 1st to 3rd upshift, no 1st to 2nd or 3rd to 4th. I do have reverse. No slippage at all, Just shifts from 1st straight to 3rd at about 3k rpm. Once in 3rd, If press the gas, will not go into passing gear, but goes back to 1st. Put it on a scanner,Computer shows no codes.  Thanks for any help.  Dan

Answer
You need to put an external trans pressure gage on it and see what pressures you have in the different gear ranges. Most likely your problem is internall with one or more of the shift solenoid failure that will NOT show up on a scanner.

Without performing the pressure test sequences your guessing in the dark.