[ampedupnj]

I've always had poor GPS performance on cell phones mounted in the vehicle and I've recently discovered its not the phone(s) issue(s), that something in the vehicle is actually interfering with GPS signal. I discovered this when using an app on the phone that shows signal levels and leaving the phone in car with the car completely off. As soon as I open the door I can watch the signal degrade substantially. It is worse toward the wireless charging mat / shifter console area and can be so bad that it knocks out GPS completely, but IT IS NOT the wireless charging mat (pulled fuse for it and made no difference).

I know its a long shot, but anyone have any idea what is creating it and what I can do about it?

Sorry, 2019 Premier. No significant mods besides hardwired dashcam.

 

[wssix99]

Do you mean that when you open the door, the signal improves?

Many of us have had problems like this, (there are old threads) but it was bad applications running on the cel phone.

You might also try adding a cel phone shut-down/reboot to your experimentation.

Where you are testing these things makes a difference. Any signal reception inside a car will be worse than outside the car, but from a GPS perspective, the difference should be negligible.

The thing that really impacts signal reception and positioning is proximity to buildings. People living in Cities get the extreme of this and know all about the Canyon Effect: https://en.wikipedia.org/wiki/Urban_canyon

^ If you are testing your GPS reception near your house or in your garage, that's a bad place to do it and you'll get false readings. If you want a scientific result, you should go to a large field or parking lot away from buildings, other vehicles, things obstructing your view of the sky, etc.

 

[Cord]

I seem to have 3 GPS apps from some time ago on my iphone
GPS Data -- GPS diagnostic -- GPS time
what are you used to see the signals data or are you just getting bad location info ?

and I will take a look but I have a 2012 Volt

- does the wireless charging pad still work with you pull the fuse (HAHA)

 

[voltreg]

tinySA Ultra. Don't leave home without one. I don't...so handy and so cheap.

tinySA | Main / HomePage

 

[ampedupnj]

The app is called "GPS Data". No, charging pad does not work after pulling fuse.

Position in vehicle.

Vehicle off. Or after 90 to 105 seconds after key off and door open (RAP shutoff?)

Vehicle on. This degrades to zero sats / signal if I place phone on the charging mat.

I know the radio module is right behind the bulkhead of the charging mat, and that is my next best guess as to what is pushing out the interference.

 

[wssix99]

What happens if you have the phone's bluetooth off, have the phone unplugged and have the phone away from the mat? What happens if you unplug all of your aftermarket accessories from the car?

What type of charging mat are you using? An aftermarket device?

Keep in mind that the phone is not a true signal meter. Only the device that voltreg posted is. The phone is making calculations to guess what is going on with signals, but bad app programming or other application conflicts inside the phone can cause perceived issues in other areas. (When you turn on the car, other parts of the phone are activated, like bluetooth connections, etc.)

 

[hellsop]

what's the gian black box up near the rear view? Does unplugging that, or any/all of the other mods you might have going on, help?

 

[obermd]

GPS signals are very weak and require line of site to a minimum of four satellites to lock on. GPS receivers can stay locked on with two satellites using the assumption that the receiver's altitude is relatively static and three satellites to handle rapid altitude changes. I've discovered that putting my phone in the storage area under the dash always causes the phone to lose sync. I keep mine in the slot next to the gear shift (Gen 2) and it's pretty reliable.

 

[Steverino]

moved to Accessories, Apps, Modifications...

 

[Saint]

Interesting. I design GPS systems for living. Do you have your wifi hotspot on? I turned it off a long time ago and don't have any issues with Pixel5. Will give it a try next time.

I've always had poor GPS performance on cell phones mounted in the vehicle and I've recently discovered its not the phone(s) issue(s), that something in the vehicle is actually interfering with GPS signal. I discovered this when using an app on the phone that shows signal levels and leaving the phone in car with the car completely off. As soon as I open the door I can watch the signal degrade substantially. It is worse toward the wireless charging mat / shifter console area and can be so bad that it knocks out GPS completely, but IT IS NOT the wireless charging mat (pulled fuse for it and made no difference).

I know its a long shot, but anyone have any idea what is creating it and what I can do about it?

Sorry, 2019 Premier. No significant mods besides hardwired dashcam.

 

[mrlinux11]

I've always had poor GPS performance on cell phones mounted in the vehicle and I've recently discovered its not the phone(s) issue(s), that something in the vehicle is actually interfering with GPS signal. I discovered this when using an app on the phone that shows signal levels and leaving the phone in car with the car completely off. As soon as I open the door I can watch the signal degrade substantially. It is worse toward the wireless charging mat / shifter console area and can be so bad that it knocks out GPS completely, but IT IS NOT the wireless charging mat (pulled fuse for it and made no difference).

I know its a long shot, but anyone have any idea what is creating it and what I can do about it?

Sorry, 2019 Premier. No significant mods besides hardwired dashcam.

I will bet your wireless charging pad is acting like an antenna and generating an RF field (whether it has power or not)

 

[dannyV]

i think you should power down that hard wired dash cam and see.. next power down that mirror.. i suspect dash cam wiring.

 

[ampedupnj]

The issue has existed for the life of the vehicle and long before the hardwired dashcam and the HIvemapper. The vehicle's hotspot is not on. Pulling the F30 fuse for infotainment (radio module) stops the interference. Not sure what to do now; may dig back there and pull individual connections trying to isolate, but there may be no way to eliminate it short of wrapping the radio module in a faraday bag. Will update post if I find anything useful.

 

[dannyV]

I just remembered there was some kknd of recall for the screen becoming corrupted, the fix was to reroute a wire that was causing interference.. I wonder if it's that same wire causing you problems.