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Discussion Starter · #1 ·
i picked up a new s4 last week and i have the 2A DVD. my SW is 0110. and it frequently has me in the wrong place - sometimes 100's of feet from my real location. i spoke to an audi service guy who said that new SW may be required - new SW cam out 3-4 months ago - but then i read some comments here and it seems that the SW comes from the DVD. so i am a little confused.

anyone experienced such innaccuracies re the maps and your location?

thx

jc
 

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Before you change anything, take a long (50 miles or so) drive with route guidance activated. It takes some time until the RNS-E is perfectly calibrated. This will also be required if you change tires.
 

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Discussion Starter · #4 ·
just a thought... does it also need calibrating IF it is not accurate when i am stopped for a minute or so too? because that also happens in some places...

thx again
 

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jc said:
just a thought... does it also need calibrating IF it is not accurate when i am stopped for a minute or so too? because that also happens in some places...

thx again
Sorry, I don't understand what you are asking.
 

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Be aware that maps are buggy too. Average update time span for Audi maps is 1-2 years.

It is different story when your navigation readings are off. In this case it could be calibrating (like Dirk said) or weak sat reception. In any case this wouldn't be a problem related to firmware.
 

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Discussion Starter · #7 ·
AudiA4B6US said:
jc said:
just a thought... does it also need calibrating IF it is not accurate when i am stopped for a minute or so too? because that also happens in some places...

thx again
Sorry, I don't understand what you are asking.
i am assuming that calibrating the system is to improve accuracy while moving. if i am stationary, stopped, not moving, then after some time one owuld think that the gps would position me accurately. that doesnt happen either. not all the time.

as for the map/road accuracy. my wifes tom tom is fine with all roads as is my 06 porsche system. i will try a drive to calibrate.

thx for feedback.

jc
 

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Remember that no GPS system that a member of the public can buy is accurate to more than 20-30 metres or so (say 100 ft). What car sat nav systems do is to guess that if the GPS position is "near enough" to a road then you are probably on that road so they show you there.

What that means is that when you are at a junction the GPS might show you anywhere from 100 ft before the junction to 100 ft after the junction, it's only if you actually turn at the junction that it know to adjust your position.

Most people have expectations of the accuracy of GPS that it cannot fulfill, but the "trick" of adjusting your position to a road makes it appear to be as accurate as people expect.
 

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Discussion Starter · #9 ·
i hear you thanks dave. thing is my confusion comes because this the the first gps i have had in a car (i have had 4 before) that is so blatantly wrong. to the point that i can miss turns or even take the wrong turn because the info relayed to me is so far out. i am enjoying the car but i am disappointed beyond belief in the nav system thus far. i remain hopeful that a drive will work.

i have reset the system to factory setings to see if that helps. another thought... the car was delievred new by audi to souther florida and it was delivered to me on a flat bed and i live in PA. as the world is not flat could it be that there is a setting on the system that gives false readings in PA because the car never drove here so never recalibrated?

jc
 

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jc said:
the car was delievred new by audi to souther florida and it was delivered to me on a flat bed and i live in PA
Aaaahhh!

Since the system was moved from Florida to PA on a flat bed it will still be looking for the satellites that it could see in Florida, not the ones that it can see in PA. So it won't be seeing that many satellites, making it's position inaccurate.

Add to that it hasn't been driven many miles, so the calibration of the number of wheel rotations per mile isn't yet accurate and you have a system that is doubly inaccurate.

It needs driving around in the PA area to sort out both these issues.

Try driving it for a week or so, and re-assess it's accuracy again then.
 

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Discussion Starter · #11 ·
hey thx dave. i am a brit-abroad and i need the guidance in many ways ;-)

we laughed this afternoon. it had me 400 yds off course in the wrong direction. it was so bad all we could do was laugh. i hope your advice helps out in the long run.

thx

jc

ps is there a setting anywhere to tell it where i am? and to force it to look for local satellitres?
 

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Stupid question but you are receiving satellites, are you? To check press the Nav-Info button when in Navi mode. 4 are minimum to determine your position. 7-8 make it much faster.
 

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Discussion Starter · #13 ·
AudiA4B6US said:
Stupid question but you are receiving satellites, are you? To check press the Nav-Info button when in Navi mode. 4 are minimum to determine your position. 7-8 make it much faster.
not a stupid Q. i am getting some - it is tracking me but not well... i will check the sat numbers. thx

jc
 

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jc said:
ps is there a setting anywhere to tell it where i am? and to force it to look for local satellites?
If you look at the bottom of the Nav | Setup page there is an option to tell it where you are and what direction you are facing in - very useful to "help along" the initial calibration!

Regarding satellites - there's nothing to tell it what to look for (that's a very complex thing to do depending on where all of the nearly 30 satellites are at any one time. Worth checking out the Engineering Mode display (use the search engine on here to get info on how to get into Engineering Mode or PM me) and see just how many satellites it is seeing and how many of them are being used for positioning.
 

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PetrolDave said:
Remember that no GPS system that a member of the public can buy is accurate to more than 20-30 metres or so (say 100 ft).
Whilst it used to be the case that the signal for public consumption was nowhere near the accuracy of the private signal used by the US military, this hasn't been the case for several years now and we all have access to the full accuracy of the GPS system.

That said, I'm not sure exactly how accurate it is but I'm positive it's a great deal better than 20-30m.
 

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Vertigo1 said:
That said, I'm not sure exactly how accurate it is but I'm positive it's a great deal better than 20-30m.
SA "Selective Availability" (i.e. deliberate "corruption" of the GPS signal using a code known only to the military) was turned off on May 1st 2000 under the terms of an order signed by then President Clinton.

Having spent the last 4 years professionally designing systems based on GPS I can assure you that without using "tricks" like differential GPS, 20-30m is typical performance.
 
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