Sensor is up front in the bumper by the fog light black mesh. It's a hole, maybe 1/2" diameter and there should be a cone shaped sensor pushed into it. If it's missing, maybe a rock hit it on the 5 freeway, then it could be loose inside the belly pan. You can access the sensor by jacking up the car and removing the front part of the plastic inner fender or removing the belly pan (easier) an reach in from behind. Either way, nothing to do with changing any filter. To be safe, stay off the 5 forever, it's way to crowded by you anyway. Is the fair over yet? Are they racing there yet?
Have the same problem. I tend to think that there is a circut problem. My intrument cluster is drawing 185 milli amps as well. I removed my instrument cluster and had it checked out. It appears to be fine. I had replaced my temp sensor before i removed the cluster (you can reach it from under the hood if you have long arms and know where to look) and no change, temp still reading 185 degrees. I am waiting to get my instrument cluster back as i shipped it to Michagan. Have read somewhere that if you unplug the instrument cluster and wait for a minute and plug it in it resets? That's what i am hoping for now.
like i mentioned above, the usual cause is a wiring issue. when the temp reads 185 there is an open circuit somewhere. the cluster will not cause this. all the cluster does is displays the temp. this is very common on the c classes.