Hello All,

I was able to obtain some gyro and wheel sensor data during a condtion of normal navigation function and a condtion of "map shift" inaccuract nav system function.

Wheel sensor readings were taken at 0 mph, 20 mph, and 35 mph. In all cases (i.e. both normal and abnormal Nav position calculation) the wheel sensor values remained the same (i.e. 0 mph - 0 value, 20 mph - 172 value, and 35 mph 320 value).

The Gyro sensor reads 2500 while at rest, and increases in value during a turn to the right and decreases in value during a turn to the left. For what it's worth, I also noticed the the accelerometer display appeared to be functioning normally.

My conclusion from this test was that the wheel sensor and the Gyro sensor are probably functioning correctly since there was no change in the sensor values between readings taking while the Nav system was providing a correct position, as well as an inaccurate ("map shifted") position.

However, there are still a number of unanswered questions about the GPS calculated position, and its influence on my unexplained "Map shift" problem.

- My green GPS symbol & Satellite indications (on the map page) refuse to appear until I move the gear selector into either forward or reverse.... is this normal? Could this delay in the presentation of the green GPS symbol be indicative of a GPS sensor related fault? I would have thought that the GPS would display its NAV ready green GPS symbol as soon as it had acquired satellites and calculated its postion irregardless of vehicle shiftor selection. Could another forum member look at their NAV display to help determine if the delay in the appearance of the green GPS symbology until a drive gear is selected is a normal function?

- I took my Garmin GPS with me during a test and compared both lattitude and longitude positions with the BMW calculated position. I have absolute faith in the Garmin system. The values of the BMW system were almost always different from the Garmin position by approximately 0.30 degrees lattitude and 0.20 degrees longitutde. For example Garmin: N 49 11.33 W 123 09.00
BMW : N 49 11.14 W 123 09.22
Is this position discrpency within an allowable tollerance? Could this position discrepancy be the root cause of my unexplained "map shift" of about 300 feet?

Any further insights into this issue would be greatly appreciated.

Cheers,

Marcus