95 Cutlass - Overdrive Issues

[saluki]

Does anyone know what would be causing my 4t60E trans to lose Overdrive after about 25-30 minutes of driving? I can get it to work again by turning the car off & on. It will work for a while before doing the same thing again. Any ideas?

[SappySE107]

Mine wasn't working at all so the brown wire going to the trans is no longer connected. Lockup works but is not longer smoothed on engage. I couldn't tell you what is wrong but you could try this out and see if it works for you. Or maybe someone has a real fix for you.

[sharkey]

this could be an electrical issue. the best thing to do would be to get a scan tool with a data stream onto the car and go for a drive till it acts up, when it does, look to see if the pcm is commanding overdrive. if its not, you have a sensor input problem (tps, map, vss, ect).