GPS no fix

I noticed today I have an issue with my. RMC unit in that it's receiving no GPS data. Initially I thought it must be the antenna but in the green screen the unit is displaying details, enough to get a lock/fix at least in theory. It would appear going on the GPS stored date that I had a fix last om 26 April. I have had no software updates or other changes in well over a year.

Anyone got a clue what the issue may be please?
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TheStigOnline

(Lives, drives and laughs in Stig)
VCDS Map User
Welcome to what I'm 95% sure is one of the common faults for poorly sealed roof antennas (the fin to the rear on the outside), what most likely happened is water or just the atmosphere over time has broken through the seal between the roof antenna/fin case and poof, no more GPS lock/fix because the electronics are now damaged.

If Presentation Mode is available in your version of software, from the Sat Nav settings menu, we can set our starting position manually and the onboard system will try to track the movements without live GPS as a workaround.


Also, there is one suggested no parts required repair method that I came across in my research of this issue before and that is to try to dry out the fin with a hair drier from just under it or by fully removing it from the roof first.

However, the best permanent fix I've done to date is a replacement roof antenna that was professionally reconditioned and we resprayed the fin it came with to match the car in questions colour code, has been great since.

Pro-tip, even with the new roof antenna it's better to seal the inner edges between the fin case and antenna base, as well as between the base and roof surface with suitable silicone sealer just in case ;)

Then it's just a matter of swapsies with the new for the old damaged fin and an easy DIY on estates/wagons/hatchbacks, not so much on saloons because of the challenging inner access.

That is if this is the cause of the reported issue and hope the above helps :)
 
Thankfully I have an Avant so getting it out wasn't too bad yesterday (after I posted this). No obvious sign of water ingress but when I unplugged it the number of available satalites shot up, only to go down again when the antenna was plugged in. So it's fair to say it's knackered!

Will try the hair drying to see if it works, worth a go as I dont lose anything if it doesn't.

Can't imagine these things being too cheap to replace from audi? Not many second hand on fleabay in the UK, and postage for ones in Europe puts them in the £80/90 range!
 

TheStigOnline

(Lives, drives and laughs in Stig)
VCDS Map User
Thankfully I have an Avant so getting it out wasn't too bad yesterday (after I posted this). No obvious sign of water ingress but when I unplugged it the number of available satalites shot up, only to go down again when the antenna was plugged in. So it's fair to say it's knackered!

Will try the hair drying to see if it works, worth a go as I dont lose anything if it doesn't.

Can't imagine these things being too cheap to replace from audi? Not many second hand on fleabay in the UK, and postage for ones in Europe puts them in the £80/90 range!

Yeah, the OP who shared that hair dryer method had great success but that was straight after a car wash and they noticed the failure, if it's been awhile then its 50/50 but worth a try and then a good spray (inside the fin and out) with suitable electrical contact cleaner at least.

As for the stealer prices, that's self evident and usually in the hundreds last I checked (depending on the specific antenna, with TV, no TV, etc.)

The last one I did was the full shebang with TV and about two thirds of the price you've mentioned above, however, that was a jammy deal :D
 

AlS3BE

Registered User
you could get an aftermarket aerial and stick it under the dash. There was a few who done this on the VW Audi forum and relatively cheap. I had similar issues with mine and luckily it was under warranty but it ended up being a big job as they ended up replacing the roof lining as that was damaged when they changed the aerial. This was an a6 saloon so not so easy for access.
 

TheStigOnline

(Lives, drives and laughs in Stig)
VCDS Map User
you could get an aftermarket aerial and stick it under the dash. There was a few who done this on the VW Audi forum and relatively cheap. I had similar issues with mine and luckily it was under warranty but it ended up being a big job as they ended up replacing the roof lining as that was damaged when they changed the aerial. This was an a6 saloon so not so easy for access.


This is another good option if its GPS only, because the factory antenna can be used for up to three types of signals (GPS, GSM/Mobile SIM, and TV) if I remember correctly.

The third-party options to look for have a FAKRA connector that usually plugs into the back of the head unit in the dash and many have reported great success with these before.

Personally, I hate to look at any fin knowing its dead and doing nothing except stopping water from entering the roof :banghead:
 

Mo-S3

Registered User
Find the same one on ebay regardless of colour and you can swap over the cover with your original. The aftermarket gps antenna will work and its usually its the only thing that dies in the sharkfin so the mobile etc still work ok
 
Find the same one on ebay regardless of colour and you can swap over the cover with your original. The aftermarket gps antenna will work and its usually its the only thing that dies in the sharkfin so the mobile etc still work ok
Beat me to it, the swappable case/cover was my next question. Thanks!
 
Sorry to drag up my thread from May, but incase anyone finds this in the search or by Google.

I bought a stand alone GPS receiver for £9 as I didn't want to pay nearly £100 for a refurbed shark fin! Fitted it today and stuck the puck it to the top of the glove box. All working properly once more!

Thanks for the tip on this everyone.
 
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