My GPS device does not pick up or lock
onto satellites ?
Some modern cars are fitted with a special windscreen that cuts down the
amount of UV (Ultra Violet) rays that will be transferred through the
windscreen which help cut down on glare. These windscreens are called
Athermic, or UV Coated and will dampen/reduce GPS signals coming through
the windscreen, so if you have an Athermic windscreen, it means you will
not receive the same quality of signal as you would do by taking the GPS
device outside of the car.
How do I know if I have an Athermic
You can either contact the manufacturer of your vehicle, or talk to the
main authorised dealer who may be able to tell you. If you cannot receive
a firm yes or no, then another way to check is to power up the GPS device
and hold it outside of the vehicle, receive a satellite fix and use the
GPS status screen to see how many satellites or what signal strength you
can see. Once you have noted this down, move the GPS device inside the
car and see if the GPS signal drops by 2-4 sats. If it does immediately
then you probably have an Athermic windscreen.
There is list of cars in the table below that we believe have had Athermic
windscreens fitted throughout part of their history. Please note that
manufacturers don't always use the same windscreens through the life of
a car model, so even though a model may be listed below, it does not necessarily
mean that the current model that you have may have an Athermic windscreen.
If you are unsure, try the above test or talk to your car manufacturer/dealership.
|BMW 3 Series
|BMW 5 Series
|BMW 7 Series
||Mercedes W220-S Class
If your car does have this type of windscreen you
will need to use an extension GPS antenna that can be placed in an area
where you will receive a signal or can magnetically fix to the roof of
An external antenna is available, call on 0161
If you still have reception problems:
- Obstructions to the open sky will reduce GPS
performance. Try to ensure placement of the GPS device away from the
windscreen edges so it has the widest view of the skies possible. With
an external antenna place it away from roof bars and at least 10cm way
from any other roof mounted items.
- Driving in built up areas and close to tall
trees reduces satellite reception.