I know that you have heard about this issue "ad naseum", however, I still cannot figure out what is going on with these two lights being on at the same time. It seems to me that there must be a common "sensor" for these two lights otherwise they would not come on at the same time and not able to re-set them. I do not feel comfortable "shorting out" the plugs to see if that specific light goes out. I was thinking about changing the level sensors on both to see if this would solve the issue, until - in another forum, someone mentioned that there was a sensor that was common to these two level sensors and that it was located under the front bumper cowling. Was this person referring to the outside temperature sensor? I have looked in the EPC and I cannot find any such sensor attached to the wiring harness for both of these two sending units. Would any one of you guys be able to help me on this? Would be greatly appreciated. 1999 S500.