TCC and Overdrive Questions
 

Hi ~

With the problems I am experiencing with my TCC and OD, I have a question or two. Under "normal" acceleration going through the 40's into the 50's, does the TCC lock first, then the tranny shifts into OD? Or does the tranny shift into OD first, then the TCC locks? Also, if the TCC unlocks (as in a solenoid failure after the tranny warms up) does the tranny automatically drop out of OD?

Thanks for your help!
John

OD first. Then TCC lockup.

TCC lockup can be checked by watching the tach and gently tapping the brake pedal once. The brakes release the TCC soleniod and you should see a 200-500 rpm increase when the brake is tapped.

If the TCC solenoid is mechanically faulty, and the TCC unlocks, do you suppose that it would also drop back into 3rd? Is there a scenario where a faulty TCC solenoid would not make the CEL light up?

Thanks,
John

There's a scenario for anything and everything is possible.

If you have questions that are aiming you this way, I'd suggest getting a good old free estimate from a reputable transmission shop.

Well see, that's the whole issue. I had a lot of work done last week:

- Replaced UIM
- Replaced LIM gasket
- New thermostat and upper rad hose
- TPS replaced
- Front and rear tranny mounts replaced
- One transmission line replaced
- Rear brakes adjusted
- New oil
- Coolant replaced.

The tranny mounts had to be done, and that was the main reason for the service. The rear one was totally gone. But anyway the *hope* was that the thermostat would correct the issue of the TCC and OD, because the motortemp was barely getting off the first hash mark on the gauge. But no, it didnt fix it. Now my mechanic feels strongly that the TCC solenoid needs replacing. And he is first and foremost a tranmission guy. But something he said (TCC comes first then OD) makes me wonder. So..thats why I asked. I wanted to confirm what I thought was the proper order of thngs. I hope all this rambling makes sense. I just want to avoid a trial-and-error process if I can; however, I DO understand that with these automobiles trial-and-error is the only way to find a problem. Otherwise I would just go straight to complete tranny rebuild.

BTW, the bill for the above work was $750. Does that seem reasonable

Thanks,
John

Ok...well then we need one of the 93 FSM owners to chime in and tell us what the good book says.

<~~~ calling to wake up an fsm owner :twisted:

Confirmed from whathisname...

You can have TCC lockup in 3rd if the proper conditions are met.

With all that stuff...there's plenty of possible things that could cause it not to happen.

When you changed all the things. Did you happen to unhook the battery for 30 or so minutes? Might be worth a try.

Ummm..no I didnt unhook the battery for 30 mins or so. I will try this later today when I get off work. I suppose this will reset the computer, then I will see what happens.

Thanks,
John

It's a shot that maybe the PCM couldn't do it because of the tps issue or something else and now it hasn't learned that you have corrected an issue.

:sleepy:

i can give you the paramaters that need to be met for TCC in 3rd and 4th