So a couple days ago my temp Gage dropped to the bottom. It will not read at all. So i changed the temp sensor- The one under the throttle Body and it didn't fix it. I have heard there is another one but cant seem to get any info on where it is at. Also since it stopped working my fans run from the time i start the car and then about 2 Min's after i shut the car off. Any ideas on this problem? And if there is another sensor where is it.?

 

Many times the code that gets thrown for the coolant temp sensor also means that your thermostat is bad. This happened to me a couple months ago, fans would run the entire time and my temp gauge didn't work. Once I replaced the thermostat everything was back to normal, in fact it just happened in my girlfriends' Saab 9-5 too. Coolant temp sensor code was thrown, I changed it, light was still on. Yesterday I just changed her thermostat and now it's back to normal.

 

Alright, Great. Its worth a shot. I appreciate it.

 

Yep, I was thinking a tstat also.

The other coolant sensor is on the radiator, to the left of the filler neck (at least that's how it is on mine)

 

Isn't that the level sensor?

I would flush the coolant (if you haven't in a while) and change the thermostat. Air bubbles can actually cause the same problem sometimes.

The fans staying on is a precaution built into the PCM when it doesn't know how hot the engine was from the gauge not reading.

 

Yeah Chibi it is, but that's the only other coolant related sensor I know of

 

I don't know placement of coolant sensors on the 3400, but I know my '94 3100 (that the 3400 is based on) has a sensor in the rear head.

 

It's Fixed. Disconnected the battery for a while and then I took off the upper Rad. hose and made sure all the air was out of the the system. Gage is now working and fans aren't coming on. Thanks everyone for the help.