95 F150 in my sig.

My original trans hard lines were rotted when I bought the truck, when I repaired that I bypassed the radiator and went directly to the stock trans cooler. This was two years ago.

Since ambient temps dropped last November, I've noticed that the truck is shifting late, and it also seems to shift into OD/lockup immediately when my speed hits 40mph at part throttle.

I installed a trans temp gauge this past summer, and during this winter the needle hasn't moved at all. I tested the sender/gauge by putting the sender in a cup of hot water with a meat thermometer in it. The gauge read exactly the same as the thermometer.

I'm going to check for codes today, even though the CEL has not been on, and the OD light hasn't flashed.

What I'm wondering is, will trans fluid that's too cold cause the E4OD to shift this way?

 

There is a Transmission Oil Temperature (TOT) sensor on the solenoid pack. The PCM does modify the shift schedule based on temperature of the oil. It is plausible that yours is not warming up enough therefore the PCM is using a cold weather shift schedule all the time.

TOT sensor location:



courtesy of subford

 

Excellent information, thank you! I had done some searching, and couldn't find a definitive answer, aside from "OMG rebuild time".

Tried to rep you, but apparently I need to spread myself around before I can do that. The wife ain't gonna be happy with that.

 

Ran a KOEO.

116-ACT out of self test range
114-ECT out of self test range
636-TOT out of self test range

It's about 30 degrees here today, and I haven't run the truck since last night, so I'm going to ignore those for the time being, get the truck to operating temp, and try again. Maybe a KOER too if this storm holds off for a bit.

 

What type transmission is in the photo?
It is not a E4OD.

 

Those are normal codes for a cold engine & transmission.
Even if you warm the truck up and if the outside temp is below 50 deg F the 116 Act code will be there.

The radiator is also used to heat the transmission oil when it is cold out.

 

That's what I'm thinking is the issue, Bill. Been doing some searching, and it appears that Classic Tube has pre-bent trans lines in stainless for $120. I do believe I've found my next purchase.

 

I posted the wrong pic, sorry...fixed, courtesy of one of your photos.