Transmission probem suspect throttle position switch
Well I still haven't fixed my trans problem yet but noticed something today when I was messing with it. While coasting in D (transmission remains in 3rd even though I have D selected) If I get on the gas about half throttle, it slips and then grabs. If I go say 75% it really doesn't slip. If I use light throttle say 25% or less it spins up high and trans program comes on and shifts abruptly if not hard into third and stays there unless I select second or first, in which cast it will go to second gear. It seems the car is always one gear behind, when I select third it downshifts to second, in drive it doesn't go past 3rd. I notice it shifts fine from first to second, then tries to shift to third but remains in second or slips then goes back to second, then it tries again and gets to third, but slips under light throttle. After that it does not attempt to shift anymore. Its as if it thinks it is in 4th but is really in third. When I drop it to third it downshifts to second as if it thinks it downshifted to third. If I select 3 it downshifts to second gear. If I select second it will go into second like it should and so on when I am downshifting. If I select manual mode and start off in first and shift to second, it upshifts just fine to second. When I select third it tries to shift but remains in second and slips and then catches second. when I then select D and switch it back to E mode, it shifts to third and slipps under light throttle but if I get on it with about 50% throttle or more it does not slip, however it remains in third. If I pass 50 mph and remain above it for more than a few seconds it beeps and displays trans program. Also If I let it slip under light throttle for more than a second it also displays trans program. in either case once it is in trans program mode there is no slipping in third like when it is not in trnas program mode. Because of the slippage at light throttle, but none at heavy throttle I am suspecting the TPS. You would think the opposite would happen where it wouldn't slip at light thottle but would slip at heavy throttle. I have gotta figure this out. How can I test the TPS and the Speed sensor on the trans? That will eliminate two things or find my problem. I recuse to believe it is a mechanical problem because when I get trans program there is no slippage in third at all.