FiveRiversGTS

Not that I really use this system for the purposes of navigation, I do however open the map to watch the traffic. The other day when I did this, the display location was not consistent with where I was located.

I did turn off the car and restart.
I did enter a route.
I did search and found older posts that mentioned to disconnect the battery which I did not do since I was not sure about it.
Perhaps I should take it to the dealer?

Still shows some wrong location.
Doesn't seem to move either when I drive.

Has anyone else had this issue and or know the solution?

Thanks for your help.

StormRune

On 997 models, this was typically caused by work that caused the GPS antenna to be disconnected followed by someone forgetting to reconnect it. Its reception is just poor. On 997s the GPS antenna is in one the passenger side on the trim near the wipers under the windshield and often would get disconnected when the windshield was replaced. I don't know where it is on 991 models.

The point is, it is likely the GPS antenna isn't working well and gets a large degree of error. Has there been any work done on the car that might explain a disconnected antenna? It might be as simple as plugging it back in.

FiveRiversGTS

The only work was installing a wire for the radar which the dealer performed about 2 weeks ago. It was from the fuse box to the rear view mirror so I could plug in my radar detector.

Not sure if I used the Nav in the interim.

Most of the posts I read were in the 997 forum.
Don't know where my antenna is for the Nav?
Is it the same for the satellite radio? Because that works fine.

Thanks for your help.

StormRune

It appears from the diagram linked here that the GPS antenna (part 10) is separate from the satellite radio antenna (part 1) and is likely located in a different position in the car, although with this diagram it isn't clear where. See: http://www.gaudinporscheparts.com/au...and-radio-scat

You can't help but wonder if it related to your detector work somehow, but maybe not. In either case, hopefully your car is still under warranty and the dealer will work out the problem at no cost to you. I'd give it a 95% chance of simply being a problem related to the antenna.

911sccab

I'd speculate the antenna problem is 95% related to the radar detector.

FiveRiversGTS

Thanks for the input. You may be correct, as they mentioned the wire would've running along the pillar, which I see in the diagram.

So far the dealer has mentioned it is likely due to the weak signals??? But I will bring it to their attention about the possibility related to the radar wire install.

Thanks. I'll keep you updated.

mrhebert

Same thing happened to my 997. It is related to the antennae being disconnected. Very easy fix.

RickIrons

This happened with my 991.1 a lot. The dealer was unable to fix it... It also happened a few times with my '13 Cayenne.

FiveRiversGTS

What is the procedure to fix this?

Did you proceed further if the dealer was unable to fix it?

My update:
1) Dealer originally states it was satellite signals
2) Now they mention it is something in the PCM settings???
3) They firmly state it is not related to the installation of the radar wire.

They are going to investigate and get back to me.

Thanks everyone for your help. Much appreciated.

RickIrons

I didn't proceed on the 991. It was one more year on the lease and it only occurred occasionally. It happened only twice on the Cayenne so far.

R_Rated

GPS tracking device will also do this

LexVan

Do we have a calibration process? I know on my old Garmin did. Go into calibration mode and then drive in a slow 360 degree circle, or something like that.

FiveRiversGTS

The only other device in the vehicle is the iPhone which I use as GPS with Waze and Google Maps and Find Friends. But it never interfered before.

FiveRiversGTS

I asked the dealer about recalibration without an answer on that question but they said they have to see the vehicle.

Do you know how to enter the mode for recalibration?

StormRune

Calibration is only used for an electronic compass, typically in a figure 8 or at least a 360. There is no calibration for GPS.

OP. The only reason a GPS produces poor readings is when it isn't receiving signals from enough satellites, typically due to interference from tall structures, too many trees, shielding from a human body (aka a bag of water), being indoors, or... a poorly performing antenna. I am certain this is the problem in your case unless you live in the midst of skyscrapers.

The only reasonable argument for accuracy in your car is if you live in the land of skyscrapers. Downtown LA is a known problem spot for example.

(I've worked on tracking apps for the military and transit systems and am familiar with a lot of the gotchas here.)