Gps...antenna or antennae? (2 Viewers)

[jdbearden]

So...I hope the most excellent cruiser crowd here can help answer a pressing tech question - where is the freaking gps antenna actually located, like definitively? The owners manual suggests that it lives within the head unit on the dash and looks through the front windshield. Or, alternatively, does it share realestate with the sat radio sharkfin as the dealership is insisting? I've seen it both ways on this forum. As you can see in the photo below the gps "tile" is greyed out and not accurately displaying proper vehicle location.


thanks in advance,

jim

 

[Sandroad]

On page 103 of my ‘17 LC navigation system owners manual, it clearly states the GPS antenna is in the instrument panel. It warns against using certain window tinting or installing devices on the dashboard or windshield because of interference with GPS signal. I’d say your dealer didn’t read the manual.

 

[jdbearden]

Agreed...that's what i read too. Unfortunately, the dealership LC tech is the one that is firmly in the sharkfin gps camp. Worse, they've handed me a four hour repair estimate to drop the headliner and check the connection.

Sigh.

 

[Hoosier Daddy]

2016-2018 Toyota Land Cruiser Antenna 86860-60340 | Toyota of Simi Valley

 

[Sandroad]

Agreed...that's what i read too. Unfortunately, the dealership LC tech is the one that is firmly in the sharkfin gps camp. Worse, they've handed me a four hour repair estimate to drop the headliner and check the connection.

Sigh.

I would think the parts diagram posted by @Hoosier Daddy would seal the deal for the dealer on the gps antenna being in the dash. How could the tech possibly tear into the headliner with that parts diagram in front of him?

 

[jdbearden]

Thanks....

Yup, I found my way over to the parts department and found the exact same thing. Took all of 2 minutes once i got to the right screen. That little piece of wire is $420 before anything gets opened. I imagine that either way, it's prolly major surgery to tear into the thing - just to get a good gps picture. Have you guys heard of anyone else with a gps problem like this?

Driving around ive been monitoring general compass direction to gps signal reception to see if there is any correlation to help support my suspicion that it is indeed the problem.

Of course, the nightmare senario is a failure internal to the head unit itself....yikes. Being that the signal reception is intermittent, im hopeful however that the antenna is the culprit.

 

[gaijin]

Of course, the nightmare senario is a failure internal to the head unit itself....yikes. Being that the signal reception is intermittent, im hopeful however that the antenna is the culprit.

Do you have anything - and I mean anything - aftermarket on top of your dash that could possibly interfere with the GPS signal? Anything mounted to your windshield with a suction cup, a carpet dash cover, bobble head hula dancer, etc.? Have you had your windshield replaced? Have you installed any electronic gadgets that might be a source of RFI? Do yo9u have a handheld GPS receiver you could place on your dash to confirm good reception?

Just some random (hopefully helpful) thoughts.

HTH

 

[Ninja Cruiser100]

For $420 you could get a nice Samsung tablet with great GPS software and a Bluetooth OBDII adapter to run Torque Pro.

No tearing up of dash required.

 

[jdbearden]

Best idea yet...

 

[jdbearden]

As a matter of fact, i did change the windshield due to rock chip damage. i know for a fact that we got the oem glass replacement from toyota but i am curious as to how this might affect the gps performance? Also, No tint added and the dash is bone stock....

 

[gaijin]

As a matter of fact, i did change the windshield due to rock chip damage. i know for a fact that we got the oem glass replacement from toyota but i am curious as to how this might affect the gps performance? Also, No tint added and the dash is bone stock....

Coincidence? Maybe not. A quick parts search yielded 10 different part numbers for the windshield glass for 2008-2015 Land Cruisers. Differences were with/without rain sensor, heated, even one with/without "shield" whatever that is. Are the GPS antennae for ALL model years in the same exact place? Are ALL windshields the same vis a vis radio signal transparency? Even though your new windshield "fits," is it beyond a doubt the correct one for your vehicle?

I don't know. That's why I still think it's a good idea to test GPS reception on your dash with a handheld GPS - cell phone app, smartwatch, many possible test instruments.

Can you correlate the beginning of bad GPS reception with the installation of the new windshield?

Good luck.

 

[jdbearden]

great lead...i'll run it down on monday. thanks!

 

[jdbearden]

Update....

Correct windshield part # for the VIN. Dang.

In other developments both the Service Manager and Lead Tech are now onboard with the real issue. Bad news...they think that it may be the head unit/internal faulty gps card. Supporting that theory and while on a ride along, they noticed that the gps signal was not always updating the little red triangle to the correct location, even with a good lat/long. Worse, no one fixes the head units, they just swap out a factory reman. So, we are down to arguing over who eats the bill over this long running problem.

Fun fact - the head unit takes into account steering wheel input and speedometer input to "fact check" the gps signal...who knew, right?

 

[gaijin]

Fun fact - the head unit takes into account steering wheel input and speedometer input to "fact check" the gps signal...who knew, right?

You might be referring to the "Dead Reckoning" capability of the head unit - designed to keep the display position updated when GPS signal is lost for short periods of time, e.g. going through a tunnel. When on road, a "snap to road" feature may also be used which keeps the display position located on a roadway.

HTH

 

[Sandroad]

Update....

Correct windshield part # for the VIN. Dang.

In other developments both the Service Manager and Lead Tech are now onboard with the real issue. Bad news...they think that it may be the head unit/internal faulty gps card. Supporting that theory and while on a ride along, they noticed that the gps signal was not always updating the little red triangle to the correct location, even with a good lat/long. Worse, no one fixes the head units, they just swap out a factory reman. So, we are down to arguing over who eats the bill over this long running problem.

Fun fact - the head unit takes into account steering wheel input and speedometer input to "fact check" the gps signal...who knew, right?

Is this the same lead tech and manager who quoted you 4 hours to R&R the connection to the shark fin by dropping the headliner? If so, get some type of agreement that if a reman head unit doesn’t work, it’s their problem. I might suggest at least ckecking the in-dash antenna as much as possible (like the connection to the head unit if nothing else) before spending big bucks on the head unit. I’m always a fan of doing the simple stuff first and I don’t have a lot of confidence in that lead tech.