I get that 37 code from time to time as well and I don't even have a trans temp sensor.

 

And you wouldn't be the first to get a code for a sensor you don't have.

 

Seems to be a "feature" in the PCM software.

 

Course you are gonna get a code for a sensor you don't have, cause it is needed. Wonder why you don't have one. Check again, maybe you missed it cause it has gotta have it.

 

On the 94-95 trucks, it wasn't always there. Had to have one of the 'heavy duty' packages in order for it to appear. On the 96 and up trucks, the temp sensor is integrated into the governor pressure sensor... so, they ALL have it.

 

ok, so I assume that would be the RH transmissions that didn't always have temp sensors?

 

Ok haven't looked for the trans temp sensor yet, If I don't have one does that mean my check engine will never turn off?

 

It'll turn off when you shut the key off. Restart it and it won't be on until it happens again.
If you have a sensor it should be in the transmission line by the transmission

 

Correct.

 

Ok I have no trans temp sensor, though I did find something that looks like a sensor just above the trans pan but it's not connected to the cooler lines. where would I find trans check valve? Will a bad plenum gasket cause the egr valve to go bad? I read up on the plenum sticky notes(great info in there) looked down the throttle body and I do have a dirty, oily film on the plenum pan. Stuck a magnet down there and it is the oem pan. Pulled the pcv and put my thumb over the hole and my other thumb over the hole in the canister on the other valve cover and I get suction not pressure, so if I'm right I got a blown plenum gasket. Will replace that and the egr valve sometime in the near future. Doesn't resolve my coolant temp issue but hopefully I can get this old girl running right.