I have a 95 S320. The check engine light came on a few weeks ago and the dealer told me it was something to do with the vacuum system and that it was nothing. He reset the light and it stayed off for a couple of weeks, but is now on again. How do I read out the error code and how do I reset the light? Any help would be greatly appreciated!

Has the engine wiring harness been replaced? If it has been replaced, disregard the rest of this, if it has not been replaced, this is a good time and good excuse to have it replaced under warranty, even if this is not the reason for the light. Once replaced, you can get down to real trouble shooting. Use the search feature and look under engine wiring harness for previous discussions. Ed

disconnect the negative pole of the battery, wait at least ten (10) minutes, then re-connect the cable back. Before you do this, ....please make sure that you have the code for your radio. Hope this helps....