MK3 Sat Nav issue - losing signal

[stjohnsmythe]

Hi all,

Recently, the Sat Nav in my car has started acting a little erratically.

It's fine driving round town at slow speeds but after about 5 minutes of driving at motorway/highway speeds it loses it's GPS signal. Once it's lost the signal, the only way to get it back is to park the car up for half hour or so, switch it off and then when restarted it starts working again.

Strangely, last night I parked the car for an hour or so in an underground car park (with no gps signal) after this the sat nav worked fine at all speeds for a good hour or so. This morning however it's losing it's signal again.

I've tried the 15 minute battery reset and 'Almanac' is listed as 'Yes' in the service menu.

Any ideas?