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East Pierce/South King County Nav Issues


Any excuse for a road trip
Apr 29, 2015
Puyallup, WA
We have an 2015 S85D. A little while ago the Nav started to wander significantly, causing problems with the TACC. My wife would find herself during her commute on 167 and 18 suddenly having the car think she was on a side street, quickly slowing the car from highway speeds to city speeds. We took the car to Tesla and they replaced the Connectivity Board less than a month ago. We'd already had the eMMC replacement done by Tesla, so this part was replaced under warranty.

Most of the time since, it's been better. There still seems to be an issue in the East Pierce County/South King County areas -- along 167/410/18. Traveling along 512/5/710 seems to be pretty consistently accurate, but she drives that route less.

Is anyone else having issues with the Nav/GPS wandering off your actual location in that area? We've owned the car since it was new, and not had any issues until the last couple of months. While she is driving that particular route more often now than before, we've driven 167/410 hundreds, if not thousands, of times, and 18 often enough to know that it hadn't happened until recently.

I've attached a track of this morning's drive from Puyallup to Covington -- or at least that's where she actually drove. The tracked route wanders off of 167 around the 410 interchange, and never makes its way back to her true route from 167 to 18.

When was your eMMC replaced? Does it happen on any other longer drives (could be a good excuse for a road trip)? I suspect the GPS is getting the correct location, but it is something to do with the display/logic. Was the screen upgraded from your old one? My wifes S hasn't had these issues, hers is a late 2017. Hope you figure it out.
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The entire MCU was replaced 1/2020. Everything worked fine for more than a year after that point. It's only in the last two months (even less than that, actually) that things have started to act up. After one hardware replacement by Tesla (the Connectivity board last month), I expect them to try to look at other causes that aren't their hardware. I think it's more likely that there's some additional hardware issue at play.

It would be an annoyance if it just affected Nav directions in that area. It's a safety issue when the TACC will suddenly slow down unexpectedly because the car thinks it's on a road with a lower speed limit.

Thanks for the input on your experience with the 2017.
I drove on 167, 18 and 410 today (and a couple other times in the past month) in my Dec 17 X with mcu2, hw3 and fsd. No issues.

I have seen the car think it is on a side street and suddenly slow down, but that was where there was major construction and the freeway was diverted.

It sounds like you have a different issue. Sorry that I don't know what it is.
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