'99 saturn sw1 trans temp senser

It's screwed into the transmission right by the transmission filter under your air filter box.Do you have a code is that why your looking for it?If so you most likely have a bad coolant temp sensor not a bad transmission temp sensor.Haven't replaced many transmission temp sensor's but replaced hundred's of the coolant temp sensor's.The coolant temp sensor is screwed into the cylinder head right below where the upper radiator hose goes on.it has two wire's going to it a black one and a yellow one.Also inspect the connector if it's corroded.If you have like a code P0711 my guess is the connector is corroded too.Unless you flat tow the car also that will set a p0711.Let me know what's going on so i can help you.

Thank you, saturntech9! I was also getting the P0711 error and Check Engine light. I had originally replaced the Transmission Temp sensor, but never knew about the Coolant Temp Sensor. Found mine to be cracked.

As a side note, my 97 SW1 uses the same sensor at three different locations; the Coolant Temp, the Transmission Oil Temp and somewhere else (sorry, can't remember the third). Also, you'll more than likely have to clear the error w/ an OBD Reader once you've replaced the sensor to get rid of the Check Engine light.

The third place the sensor is used is the air inlet temp sensor.

Lightbulb went on as soon as I read your reply, saturntech9. I remember seeing it there. Thanks for the update.

No problem thats what were here for.