Steel Warrior

Just took this pic of the left side of my 90 S4 auto trans, which one is the temp sensor? I'm guessing the brass one but just wanted to be sure. Thanks.

SeanR

Yep, the brass one is the trans temp sensor.

Mrmerlin

and when you remove it the whole cable must be turned or you will damage it

PorKen

The other is the transmission protection switch (for the EZK).

(The green thing is the vacuum modulator.)

Mrmerlin

I thought I would link this repair as well .
Transmission protection switch fix for leaking
NOTE this repair is for the knurled cap under the brass temp sensor.

https://rennlist.com/forums/928-foru...tection+switch

StratfordShark

What does trans temp sensor do?

Steel Warrior

Does that black wire pull off the back of the sensor or do I need to follow it to a plug connector?

ammonman

It doesn't pull off.

Mike

Mrmerlin

follow post 3 to remove the temp sensor,
think of it as an O2 sensor where the whole cable must be turned to unscrew the part

Steel Warrior

See link below, I don't want to remove the sensor, just want to disconnect it and see if it's the reason the fans won't stop until 20 mins. dr bob suggested disconnecting it and testing it, so where does it disconnect so I can test it if its like a O2 sensor?
I'm certainly not an auto engineer but why have a temp sensor way back at the trans in the engine cooling fans circuit, makes no sense to me.

https://rennlist.com/forums/928-foru...o-shutoff.html

SeanR

I've noticed a few GTS's that do not have this installed so I'm going to try and see what getting rid of it does on mine. Can't say if all of them do not have it as I've not looked at all the GTS Autos I've had in here.

Mrmerlin

that part connects in the spare tire well,
thats where I would look first,
the part screwed into the trans is simply a thermocouple.
not much to see