Anyone else have a problem with their cell phone's GPS signal degrading severely in the car? Google maps is pretty much useless now. It takes forever to compute a route (and half the time just gives up), and sometimes loses the car's location while driving.

 

As I understand you, it is your personal mobile phone that loses the GPS satellite signals when it's in the car, not the satnav. This is to be expected as the signals are of very low power, and you are surrounded by a big aluminium shield called a car body shell ! Most cars with satnavs have an external antenna, like the BMW "shark fin". The antenna on a mobile phone is tiny in comparison. Most times they will continue to receive the terrestrial phone signal which is more powerful with the base stations usually close.

 

I have no such issues with my iPhone. From the pic in your signature, it looks like you have tinted windows. Is the tint metallic tint? If so, that may be blocking the signal. I always use ceramic tint on my vehicles to avoid reception problems in general.

 

Yes, but it seems to be much worse in the XJ than in my old 335i. It was at least usable in the BMW. And the roof of the XJ is almost all glass, so it should get better signal, unless the tint is metallic (some are).

 

Hello fellow forum members,

I've had the privilege of driving various types of vehicles, some equipped with Apple CarPlay, while others are not. One assumption I've made over the years is that cars with official Apple CarPlay likely utilize an external antenna for their GPS functionality. That being said, I've never noticed any significant impact on GPS performance due to this hardware setup, until recently.

Recently, I encountered a perplexing situation while driving a 2012 Jaguar XF. Regardless of the smartphone used, the GPS seems to malfunction within the confines of this particular vehicle. The issues range from unreliable routing on various apps to a struggle with pinpointing an accurate location. This unexpected GPS inconsistency has left me utterly baffled, as it is not something I've experienced in other vehicles.

To provide a bit of context, these issues do not surface when I'm using a Mazda 6, a BMW 5 Series, a Rolls Royce, or a Mercedes E Class. What's noteworthy is that none of these cars are equipped with the official dealer version of Apple CarPlay. This raises the question as to why the Jaguar XF stands alone with this GPS inconsistency.

I find this situation intriguing and am reaching out to this knowledgeable community for any insights or similar experiences. Has anyone encountered a similar issue with the GPS functionality in certain vehicles? Might there be any known compatibility issues between certain car models, Apple CarPlay, and GPS functionality? Any advice or shared experiences could be instrumental in addressing this peculiar situation.

I look forward to engaging in an enlightening discussion with you all on this topic.

 

realmartinjames, if you are using a map program/app on a cell phone, whether the car itself has GPS or a Nav program is irrelevant as the two do not communicate with each other. So, you can rule that out. The only instance where I can see the built in radio having an effect on your cell phone is if you have a data plan and you are using the car as a hotspot. Then I could see a bit of change between vehicles. But, this should be to the good, not the bad.

Keep in mind that an aluminum vehicle is structurally thicker. What I mean by this is that aluminum does not have the strength of steel if you look at 2 pieces that are the exact same dimensions. To make up for this, more thickness of aluminum is used to get the structural strength. This is still less weight overall as compared to steel, but you have more physical material by volume. This is most likely the difference. Now, you start adding in solar treatments to the glass and using metallic films, this will degrade the signal even more.

Something you may want to try is having the car parked somewhere and open up the sunroof. Hold the phone outside the car and let it get a signal and then bring the phone into the car and close the sunroof. See if that has a significant effect. You can then rule out a lot of other factors than the car. Keep in mind that GPS units need a minimum of 3 satellites to triangulate its position (normally it is using 6 and 7 to do this). Some of these are going ot have a weaker signal. So, you start interferring with this signal, you can make the GPS unit take time and try and figure out that signal. Hence the long lag times.

I have gotten some training on GPS and how it works, but more from the satellite point of view, not so much from a GPS device point of view. Gotta love the military.

 

Exactly like Thermo write. The vehicle create so called faraday cage: https://en.wikipedia.org/wiki/Faraday_cage
Another big effect between vehicles are the heated windshield. It´s full of tiny wires closing the cage even more. If the XF had the heated windshield and other did not, there is one more reason. GPS signals are pretty weak compared exsample mobile network, what have baystations on earth surface.