GPS looses accuracy on back roads / highways

[stonekutters]

On my 21 LX we are on a road trip and on certain back roads / highways it loses accuracy while driving.

Example: the California PCH Hwy 1 from Fort Bragg to Legget passes through a thick forest over hang. During this route the GPS doesn’t track the car as always being on the road and had us going off several times.

Is this common / expected? I haven’t seen such inaccuracies on the iPhone + Google Maps. Thanks!

 

[Angelo1]

On my 21 LX we are on a road trip and on certain back roads / highways it loses accuracy while driving.

Example: the California PCH Hwy 1 from Fort Bragg to Legget passes through a thick forest over hang. During this route the GPS doesn’t track the car as always being on the road and had us going off several times.

Is this common / expected? I haven’t seen such inaccuracies on the iPhone + Google Maps. Thanks!

I don’t use the Nav. We were on 200mi. trip to Atlanta last week and both our Waze and Apple Maps tried to divert us multi times. Not sure what the heck is going on but it was really frustrating. We had to reload maps a couple times and once Apple Maps wanted us to do a freaking u-turn on the freeway. Maybe the satellites are being hacked

 

[GordJ]

IMO, the Denso software is weak. It’s a shame that we can’t install other mapping software or, even, update the maps at a reasonable cost. Like me you have to let it go and just accept that the gps and maps will not always match. And remember to drive by looking at the road and not the map, lol.

 

[hankinid]

Since GPS runs on satellite positioning that sends one or more signals to the truck, you need to have a relatively clean line of sight to the sky. Tunnels and relatively thick forests tend to attenuate the signal. The system will reset once it has a stronger signal. It's not a software issue, it's the GPS system.

 

[RET2]

Since GPS runs on satellite positioning that sends one or more signals to the truck, you need to have a relatively clean line of sight to the sky. Tunnels and relatively thick forests tend to attenuate the signal. The system will reset once it has a stronger signal. It's not a software issue, it's the GPS system.

Electrons get the 'Rona too.

 

[Angelo1]

The smart phone is just so much easier to use. Our bmw and Porsche navs are good but we don’t even use them. If I end up getting the Escalade, I could see using it as the augmented nav system looks really slick and leaps ahead of my my iPhone maps

 

[stonekutters]

Thanks folks. We mainly use Google Maps for 90% of city driving. On longer road trips is where we use the built in nav especially for offline reasons.

The real-time traffic updates on the built in system have been mighty impressive!

 

[LCNOLA]

I just did a trip from Louisiana to Asheville, NC and back. I have the Navi plus wireless CarPlay unit installed but ended up using the OEM nav more than a few times because the apple/google/Waze maps all cell signal and store nothing locally.

The OEM nav messed up a few times as well, toward the end of our return trip it just decided to bug out in a clear and well populated area.

Basically no one great solution all around. Kinda sucks honestly.

 

[stonekutters]

Agree. We did combination of offline Google Maps, offline GAIA GPS, and cars nav unit.

 

[Fisher23]

On my 21 LX we are on a road trip and on certain back roads / highways it loses accuracy while driving.

Example: the California PCH Hwy 1 from Fort Bragg to Legget passes through a thick forest over hang. During this route the GPS doesn’t track the car as always being on the road and had us going off several times.

Is this common / expected? I haven’t seen such inaccuracies on the iPhone + Google Maps. Thanks!

it is the Toyota MAP not the GPS.

I have had that problem many times. I even install the newest map as of 11/2020 ... the problem remains.

I checked the GPS numbers on the NAV with my garmin, same numbers.. but different place on the MAP.

This is a fine example, I'm traveling down the road on the right.

 

[MCtree]

Has anybody found a solution to this GPS error?

My 2021 LC also has this issue. It shows my location as being a couple miles off here in Houston. I guess it has a snap-to function where it guesses I’m on a road and it tracks me on that road, but that road is a couple miles off from where I actually am.

I have seen this gps issue a couple of times before on my LC and it’s gone away on its own - self correcting.
But this time it’s been a couple of days.

Anybody know how to do a reset on the GPS (preferably without resetting all my other settings on the vehicle)?

 

[Fisher23]

I have not.

When I compared the GPS coordinates on the Toyota NAV with a Garmin they were the same numbers BUT the Garmin showed me on the correct location on the Garmin map, but the NAV did not. This confirmed it was not a GPS signal issue.

I talked with the dealer about it and they had no fix other than suggesting to install the new map, which did not fix the problem.

 

[MCtree]

How does one check the GPS coordinates?
I’m curious if my GPS does the same as yours and has the right location but puts it in the wrong place on the map.

When I first drove my LC this morning (it was in my garage all night) it had the correct location on the map. But somewhere along the line, it went awry.
So it now shows my location on the map as being a mile or so off from actuality.

One other thing I noticed; the compass is 180 degrees off. When I am in the LC and pointed south, it says I am going north.
I wonder if this is another symptom or if it’s the cause.

 

[Fisher23]

To get the coordinates:
Click on the circle with the arrow at your location; then click MARK, then click on the circle with the red arrow again and the address and info box appears. Then click on the info box for the numbers. When you are done you can delete the address from your address book.
You can cross check the numbers with google map or another GPS system such as your phone

 

[MCtree]

To get the coordinates:
Click on the circle with the arrow at your location; then click MARK, then click on the circle with the red arrow again and the address and info box appears. Then click on the info box for the numbers.

Ha! Genius! I should have thought of that!

But also in mucking around just now, I see that you can split screen the nav screen so half of it shows a compass (under the options button you can see on the map). In that mode it also shows one’s latitude and longitude below the compass.

For me, it showed the wrong latitude and longitude.

But in looking through the Nav system manual, it does tell one how to manually position oneself on the GPS system. (Under setup, NAV, then detailed setup, then calibrate.)
It also lets one calibrate for tire changes.
After manually correcting the location and direction, I hit the Tire Change calibration and it said it was now in calibration mode (even though I have had these tires for 13 months now).

I guess I need to drive around a bit now while it calibrates.
Hopefully this fixes my issue.

 

[Fisher23]

What year is your vehicle? For tire calibration I press the button that is located under the dash near fuel door release. Do you know if the method you mention is any different?

 

[gaijin]

What year is your vehicle? For tire calibration I press the button that is located under the dash near fuel door release. Do you know if the method you mention is any different?

The two are entirely different.

The button under the dash is used to initialize the TPMS sensors after setting the cold tire inflation pressure. The Setup calibration on the Nav is used to calibrate tire diameter v. distance so that dead reckoning by the GPS unit will be more accurate.

HTH

 

[MCtree]

Mine is a 2021.

I did have slightly larger tires (275/65 R18’s) installed and a aux battery installed.
It seems unlikely to me, but it’s possible either one of those is messing up the GPS.

I’ll look for a tire calibration button, but I’m pretty sure there isn’t a physical one on my LC.

 

[gaijin]

Mine is a 2021.

I did have slightly larger tires (275/65 R18’s) installed and a aux battery installed.
It seems unlikely to me, but it’s possible either one of those is messing up the GPS.

I’ll look for a tire calibration button, but I’m pretty sure there isn’t a physical one on my LC.

Check page 484 in your Owner's Manual - check around under the dash and you'll find the physical button:

HTH

 

[Fisher23]

That button I use when I lower the tire pressure or inflate the tires.