V70: Stereo/SatNav/Phone 300 yards destination adrift

[Spike56]

As a slightly different point. Think postcode lottery. The postcode is NOT a specific house designation, rather it is a postal devised 'block' of addresses (in a town) or an area coding (in more rural areas). Usually the more specific the address, the more accurate the location. So postcode, road name and house number is going to be more accurate than just the postcode.

A little like being the only house in a village as opposed to being a house in Sevenoaks.

If that makes sense?

SatNavs work from multiple satellite signals. As stated in an earlier reply, follow the map (without a destination) and if you travel along a road, are you in the correct place? Take a turn off, does the map show where you turned? If the map is accurate all settings should be the same. If the basic map is off, even slightly, then the satellite positioning is off and would need sorting.

[AB100]

Hi All, just joined this forum and this topic is exactly what I was looking for!
Just returned from a trip to the Alps area and completed 3700 miles with absolutely no problems whatsoever with the car - except for the sat nav being inaccurate!
There were several times where it was obviously up to 100 metres out and was on the wrong road if they were close!
This is not the destination, but on the route.
It was also slow at several major junctions!
We have had 2 cars before with Here mapping and are aware of the short comings of their maps, ie usually new traffic islands etc but obvious, but this has been the first time this has happened.
The navigator kept an eye on her phone and a real map luckily and saved many miles!
Does anyone know if there are any possible problems with the gps system or receiver on these cars that may need attention?
Many thanks,
Alan

[1monkey600]

Originally Posted by AB100

Hi All, just joined this forum and this topic is exactly what I was looking for!
Just returned from a trip to the Alps area and completed 3700 miles with absolutely no problems whatsoever with the car - except for the sat nav being inaccurate!
There were several times where it was obviously up to 100 metres out and was on the wrong road if they were close!
This is not the destination, but on the route.
It was also slow at several major junctions!
We have had 2 cars before with Here mapping and are aware of the short comings of their maps, ie usually new traffic islands etc but obvious, but this has been the first time this has happened.
The navigator kept an eye on her phone and a real map luckily and saved many miles!
Does anyone know if there are any possible problems with the gps system or receiver on these cars that may need attention?
Many thanks,
Alan

Did you happen to have a roofbox or bikes on the roof?

I can't say that I have seen much problem with running on a parallel track (only a couple of times and that has usually been in roadworks where you have to cross carriageways) but it definitely slows down the response of the screen on my MY2016 xc70 if I have something on the roof. I.e. The map shows us coming up to a junction to turn but is definitely lagging behind as, frequently, the car has already passed that junction.

Empty the roofbox of skis, walking poles, etc and/or remove the bikes and mapping is back to normal with the arrow on screen keeping up with the cars actual position.
The sharkfin antenna is obviously picking up interference in my case and it just needs greater attention to how far the next junction actually is.

My old Toyota had the GPS antenna under the dash, in the same area as you would have a stand alone Tomtom, for example, and those didn't have the same issues with stuff on the roof.

[apersson850]

If the car can't find the position via GPS, it reverts to inertial navigation. Such systems has an inherent drift. They need to be recalibrated via GPS frequently.
If the car has to fall back to inertial navigation too often, and for too long, then this can happen. I have a friend where this happened, not just temporarily, but for a long time. The car ended up thinking it was in the sea, north of Denmark, pointing south, when it was in southern Sweden, pointing north.
We could easily see that the reported position (lat/long) was way off.

[AB100]

Hi, thanks for responses!
Nothing on the roof this trip as no snow, only touring!
Also mostly in the open and driving some of the famous passes ie not under forested roads.
On one occasion it led us through a village to a church yard car park which was a remarkably similar route to the real one which originated over 200M earlier but where the church end position (dead end!)was close to the real pass road!
We did wonder if there might be a problem with the car receiver or perhaps being thrown off by the rather large 'rocks' in the area as can happen with compasses!
Where it was incorrect, usually the right track was actually there on the map (latest update), so not just out of date map problem.
There were several occasions when at crucial junctions it went blank, ie no route, and then recalculated, but too late. Map displayed was correct though.
There is no substitute for looking for the roadsigns, which I am sure many of you will know, particularly in France, they are often on the other side of the junction.
Think I will report on next service but go back to TomTom, which I can use in my classic anyway!