Faulty Trip Computer?

kr9600 · Post by **kr9600** » 02 May 2011, 07:56

I recently had the turbo replaced on a 1995 850 along with two oxygen sensors. I don't believe the battery was ever disconnected as the radio worked after I picked it up from the repair shop.

I live about a half hour from the shop and the trip speed is usually 55 to 60mph all the way home. Toward the end of the trip I decided to try the trip computer as I was told that replacing the oxygen sensors could give me a bit of a boost in gas mileage. I was surprised to find the average miles per hour as 21. I then checked the average MPG and found that to be 16 and change. I knew this had to be wrong because prior to the repairs I was consistently getting around 23MPG and was hoping for some improvement.

The other trip computer functions appear to be OK - total miles, miles to zero gas, temperature, etc. Does anyone have any idea as to what the problem may be and how to correct it? Is there a general reset on the trip computer that could correct these problem areas?

Any assistance would be greatly appreciated.

Dave

billy · Post by **billy** » 02 May 2011, 08:11

If your mileage and avg speed have dropped, but miles driven appear accurate.....there is a good chance either you or the repair shop idled the car for quite a while. You can reset each and every function on the trip computer(the reset button, I am sure you see on the right of steering column) will reset each function when you reset while in that particular function. Another tank of gas will probably start showing your real avg.s

FCPEURO · Post by **FCPEURO** » 02 May 2011, 14:32

I would do what Billy said and reset all the settings. The reset button is on the same switch as the knob that causes it to rotate through the menus.

Post by **BEJinFbk** » 02 May 2011, 15:04

I would blow off the computer entirely. It's a toy.
It's not good for much more than entertainment value...
Calculate old school with gallons/miles per tank if you want accurate results.
Just one guy's opinion, FWIW.

Post by **jblackburn** » 02 May 2011, 18:30

Hold the reset button on each setting and watch them. I've never used the average speed, but the MPG figures are usually accurate on my car.

The miles -> 0 thing basically sets at 25 when you get low on gas. Don't trust that one.

Post by **VCA** » 02 May 2011, 18:36

jblackburn wrote:The miles -> 0 thing basically sets at 25 when you get low on gas. Don't trust that one.

Interesting, on the '99 S70 and on my S80 it basically goes to 0 when I'm low on fuel.