Ed,

There FSS offers some flexibility in how it measures service intervals based on driving conditions. When only wrench(es) are displayed, the FSS is counting down in miles (or km) to the next service interval. Whenever the vehicle is driven with any frequency, the FSS will be reporting the DRIVING DISTANCE remaining until the scheduled service. But let's say the Crossfire is driven infrequently, the FSS recognizes that the distance interval will not be attained in a reasonable timeframe (say less than 2 years - I'm not sure exactly how it is calculated). The FSS then switches over to displaying the clock along with wrench(es) to indicate the NUMBER OF DAYS remaining until the scheduled service.

If the service message is preceded by a MINUS SIGN it means that the service term has passed. The -150 you were seeing is suggesting that the service should have been performed 150 days ago. I'm not sure why it would not count up by +1 each day. Unless the FSS was not reset at the last service, it is time to perform the scheduled service now.

From my personal experience (2004, 21K miles) I usually only see the distance until service. But a year ago the clock was displayed as I had driven less than 3K miles in nearly two years at which point I performed the service and reset the FSS. Right now it's reporting distance again. Generally, I change the oil once a year and don't pay much attention to the FSS after resetting it. In the early days of the Crossfire there were frequent reports from new owners of the clock being displayed. It was typically the result of the car sitting on the lot for many months if not a year or more.

Rob