I have an 08 TLS with 29.7K on the odometer.


I typically reset the trip computer on fill up and will watch my mileage as I drive and use up the gas in the tank. So here is what I have noticed recently on my trip computer -

For what seems to be roughly half the tank, the trip computer calculates AVG MPG and AVG MPH for what seems to be correct - I know and have read all the treads where this is just a guide and is typically off a couple of MPG. Then what happens - not all the time - the AVG MPG and AVG MPH seem to reset by themselves. The distance and time traveled remain as they were and continue to move just as expected as I continue to drive. It's happened more frequently of late and just happened this evening. I had about 180 miles on the current tank and was averaging roughly 28 MPG and 30 MPH. I left work and went to my daughter's school to pick her up. I parked in the lot, turned off the car and waited for her. When she came out I started the car and headed home. At the first red traffic light (about .5 miles) I hit the trip computer (to display) and the trip computer showed 15 MPG and 12 MPH.
The MPG and MPH moved up and down fairly quickly as you would expect after reseting.
Anyone have any thoughts? I know I can have this looked at under warranty at the dealer, but not sure I'm going to get anywhere as they will need to see this happen - which isn't going to be easily reproducable.

Thanks in advance -

 

Anyone?

 

.