Nav gets disoriented

If you have the GPS icon in the upper left corner of the map, it has enough satellites. To see the actual satellite signals, you have to put the MFD in diagnostic mode. There are two ways to do this.

Method 1
(a) Start the HV system.
(B) While pressing and holding â€INFO†switch, operate light
control switch, OFF " TAIL " OFF " TAIL " OFF "
TAIL " OFF.
© The diagnostic mode starts and the service check screen
(â€System Check Modeâ€) will be displayed. Service inspection
starts automatically and the result will be displayed.

Method 2
(a) Start the HV system.
(B) Switch to the â€Display Check†screen.
© From the display adjustment screen, touch the corners of
the screen in the following order: upper left " lower left
"upper left " lower left " upper left " lower left.
(d) The diagnostic mode starts and â€Service Check†screen
will be displayed. Service inspection starts automatically
and the result will be displayed.

However, I don't think it is the satellites that is the problem. Probably the programming just takes longer to readjust. Remember, disabling the speed sensor intentionally introduces a problem: the car can't detect that you moved. GPS is used for recalibrating your position, not for foot-foot movement.

 

Don't know how many times it has to be said, but by disabling the speed and turn sensors with a Nav switch, you eliminate the ability to dead-reckon, which drastiaclly reduces local accuracy of the Nav system. GPS alone, even with max sats in view, will be inaccurate if you make many small motions (turning and small distances).

 

You can't disable the turn sensors. It is a solid state gyroscope and I believe it is built into the NAV ECU.