91 SE. Auto not shifting out of 2nd. All help is welcome.

[AzzyKeralis]

Recently my car has come to the point of failing to shift out of 2nd gear. It started with slipping and hard shifts them came to this, so its probably a mechanical issue and not a problem with the TCU or wiring, but I wouldn't rule it out. I did pick up a rebuilt auto trans to drop in but want to make sure that it is a problem with the original transmisson and that If I put the new one in it will not do the same thing. Unfortunately I cant do the self diagnosis Becuase the bulb on the OD lamp is out and I don't know what bulb to replace it with. From what I've read so far it can range from: stripped gears, bad torque converter, bad shift solenoid, clogged fluid paths, a short I'm the wiring, and many other things. When I drive it In "D" it will creep toward, and shift into 2nd like it should. But when it is in the proper range to shift into 3rd it will act like it is in neutral. Pressing the overdrive button on or off has no effect on it. If the selector is in "2" it will lock it to 2nd and first, and will slip into neutral at higher speeds or rpms when In 2nd gear. I have no idea what is wrong.

[Shadowgundam'93]

I had a very similar problem and did a lot research with no real answer found. I wound up doing the 5 speed swap not wanting to spend the time and money replacing the auto trans and it being the TCU or wiring in reality.

[jza80king]

i had this same issue and ended up being the shift solenoid on the transmission. Once that was replaced the car shifted normally again.