TC lockup question.

[acsho]

My 94 ATXs torque converter isn't locking up even after the temp guage is almost up to the middle of the guage. I can let the engine warm up and it still only locks up after about 10-15 miles of driving, it is killing my gas mileage because I only drive 8 miles each way to work. Does the temp sensor for the ECM have anything to do with this?

 

[rubydist]

iirc, it looks at both the engine coolant temp and the trans fluid temp and both need to be above the specified value for it to allow tc lockup.

 

[hawkeye18]

The TC lockup is controlled by the ECM via the TOT (transmission oil temp) sensor. The TOT is located either right on top of, or inside, the tranny (I can't remember). If it's bad, then it won't ever lock up.

I hate to say it, but your case sounds pretty normal. The tranny cooler doesn't have a t-stat on it, so it is cooling all the time. Even when it's really, really cold out. I've found that doing some moderate torque braking warms the fluid up pretty darn quickly.

 

[Axianator]

Jason is correct. As is the case with most transmission behavior functions on the ATX SHO, torque converter lockup temperature is governed solely by the TOT/TFT (Transmission Oil Temperature or Transmission Fluid Temperature, respectively) sensor on the transmission unit itself. Faulty TFT sensor operation, in addition to the extreme cold weather ambients that most of us have been experiencing, can lead to an extended wait in converter lock-up times from a cold start.

 

[acsho]

My 94 ATXs torque converter isn't locking up even after the temp guage is almost up to the middle of the guage. I can let the engine warm up and it still only locks up after about 10-15 miles of driving, it is killing my gas mileage because I only drive 8 miles each way to work. Does the temp sensor for the ECM have anything to do with this?

Thanks for the info guys, I assumed it had to do with the trans temp itself. But I think my sensor my be on it's way out, because it takes it just as long to lockup on a 55° morning as a 20°, but when the outside temp is above 65° it locks up immediately.

 

[CheckerSHO]

I noticed mine doing the same thing lately since it's been getting cold. I get straight on the interstate and then drive about 45 miles to work and sometimes it takes halfway there before it locks up. I monitored TFT with an NGS and it seems to be operating properly..just takes forever to warm up. I don't like it either

 

[hawkeye18]

A common solution to this problem is to staple or otherwise attach a piece of cardboard over part or all of the transmission cooler. This will block much of the cooling power, allowing it to warm up much faster. Just make sure it doesn't get too warm. And don't forget to take it back off in the spring!