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Caution - Annual Service - Car power-down - GPS issue

jfischer

Member
Feb 6, 2014
186
246
Houston
Sounds like for some reason your VMS rebooted / reset which caused the GPS to power cycle. If you have one of the "faulty" GPS units, power cycling the VMS or an Annual can trigger the issue. Mine was an annual service that triggered

If you VDS shows an older date in the 2000 range, mine at times showed 20-40 years ahead for some reason initially, its most likely a GPS issue.

Tesla has a TSB on the issue with the appropriate cables to fix it. Think they want 300-500 to fix the issue currently which I find incredulous as its a FIRMWARE issue...

If you feel you are capable of doing it yourself @slcasner has mode a cable that works by pulling the VMS cable under the passenger side and upgrading it from there. Mine was WAY more involved and required pulling the passenger side tire and patching it from their. His way is SO much easier!

Contact him and see if you can borrow it, as it just needs to be done once...at least for the next 19 years....until rollover happens again!

Good luck!
 
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gregd

Active Member
Dec 31, 2014
2,531
1,768
CM98
Sounds like for some reason your VMS rebooted / reset which caused the GPS to power cycle. If you have one of the "faulty" GPS units, power cycling the VMS or an Annual can trigger the issue. Mine was an annual service that triggered
So, one difference in this past service event was that the OVMSv3 reported APS Disabled, which it hasn't done in the past. However, the GPS week issue didn't appear until 2 days later. If disabling APS drops power to the VMS, I can see your point, but why the delay?

Grepping the logs for "VMS", I see that the VMS was restarted (3 times within 3 minutes!) during the initial annual service event back in August. No records of a restart since then, nor with a date code of 2000, so I'm guessing that APS disable doesn't affect the VMS. Interestingly, there is also a record of "GPS thread was gone for 30 seconds" back in September. No clue why, but no ill effects as a result.
 

slcasner

Active Member
Feb 20, 2011
1,172
789
Sunnyvale, CA
Oh, an idea just hit me: If the linux system in the VMS is running ntpd using the GPS sensor time as input, then what you might have observed is the long time that ntpd takes before it will give up on its own notion of the correct time and start believing an input that is significantly different. This is protection against "falsetickers", so named by Dave Mills, AKA Father Time, the creator of the Network Time Protocol.
Well, scratch that idea. An informed source told me that the VMS is not running ntpd but just sets its real-time clock directly from the NMEA sentences received from the GPS sensor.
 
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gregd

Active Member
Dec 31, 2014
2,531
1,768
CM98
I'm also assuming that since it appears that the VMS isn't turned off during an annual service (even if APS is disabled?), the power to the GPS isn't dropped either. And with my GPS flipping out a day or two after the service, it's not a matter of power being the trigger; something else is going on...
 
Oct 22, 2011
202
120
Reston, Virginia
Yes, it arrived there today. I hope it works smoothly for him.
I have successfully updated my GPS sensor using Steve's update connection box. I want to thank Steve for all of his assistance.

As these things go, I may have had two issues. In addition to the date rollover issue, when I went to update my GPS sensor, I could not connect to it.

Turns out, there is a plastic connector for the GPS sensor in the left-front wheel well behind the headlight that is clearly not weather-resistant. Over time, and maybe with no data going through this connector for the past several months, the pins in the connector must have built up enough corrosion to keep a solid connection from occurring. Using the update box, Steve helped me diagnose that I likely had an open connection somewhere. Sure enough, once I found this connector and used DioxIT contact cleaner (Caig DeoxIT Liquid Contact Cleaner & Rejuvenator, 2 mL) on it, I was able to connect to the GPS sensor using Steve's update connection box, and update the GPS sensor firmware to the latest.

The VDS now once again shows heading and elevation data, and OVMS shows location data!

Here is a photo of the connection to the GPS sensor which is in the left front wheel-well under the headlight assembly in which the pins inside apparently became corroded enough to not make a data connection:

IMG_20191222_100530.jpg


P.S. I really wish that Tesla had used stainless steel or non-rusting clips behind the bolts in the wheel wells. If you do have to go into the front wheel wells for the GPS, headlights, 12 volt battery or whatever, when re-assembling things it really helps to put a little ant-seize compound (such as LM 508 Anti-Seize Compound) on the threads of the bolts that go through these clips. It will make future disassembly so much easier.
 
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slcasner

Active Member
Feb 20, 2011
1,172
789
Sunnyvale, CA
So, who's next in line?

@ShawnA requested first, so I've asked @JohnGarziglia to send the cable to Shawn (also, the distance is shorter). Presuming that Shawn is able to complete the update quickly, there may still be time for it to go to you first before it needs to come back to me by January 15. Let me know if you have any plans to be near Sunnyvale in early January.
 

gregd

Active Member
Dec 31, 2014
2,531
1,768
CM98
@ShawnA requested first, so I've asked @JohnGarziglia to send the cable to Shawn (also, the distance is shorter). Presuming that Shawn is able to complete the update quickly, there may still be time for it to go to you first before it needs to come back to me by January 15. Let me know if you have any plans to be near Sunnyvale in early January.
Hi Steve, I probably will be down there in the next couple of weeks, though probably not with the Roadster. I'll let you know by PM once schedules settle out. Thanks!
 

Dr No

Member
Mar 20, 2016
12
3
Austria
I tried to update via the FHC47 connector ( I used singular Pins/Nails) the Powersupply came from a USB Port an I usd the RS232 connector of my computer and than I tried a USB/RS232 Adapter but I couldn`t get a communication between the Computer and the GPS Modul.
I have a 2008 1.5 Roadster.
Any Ideas what`s the problem?

Clemens
Unbenannt.png
Unbenannt.png
 

slcasner

Active Member
Feb 20, 2011
1,172
789
Sunnyvale, CA
I tried to update via the FHC47 connector ( I used singular Pins/Nails) the Powersupply came from a USB Port an I usd the RS232 connector of my computer and than I tried a USB/RS232 Adapter but I couldn`t get a communication between the Computer and the GPS Modul.
I have a 2008 1.5 Roadster.
Is your Roadster showing a date in 2000? If so, that would be very interesting because my Roadster US VIN 33 has a GPS 18 LVC (rather than GPS 18x LVC in the 2.x cars) which is claimed by Garmin not to need or have any update. However, I am able to communicate with the GPS sensor in my car and see the data stream of NMEA sentences.

Do you have the same symptom as @JohnGarziglia where the date and time were correct but the location was not being shown? If so, his problem was corrosion in the connector near the GPS sensor behind the left front wheel.

Do you have an oscilloscope or multimeter? Or perhaps a friend with such equipment and skills? It would be interesting to see if there is any activity at all on the wire carrying the data transmitted by the sensor, which is pin 9 of the FHC47 connector. Hook the ground lead of your multimeter or scope to pin 2 and the positive lead to pin 9. If your car has a GPS 18x like the 2.x cars, then if the sensor is alive but just not sending any data you should measure -5V DC and near 0V AC. But if it is a GPS 18 like mine, then you should see near 0V for both DC and AC. If the GPS unit is sending data continuously you should see somewhere closer to 0V DC and up to 5V AC for the GPS 18x or about 2.5V DC and AC for the GPS 18.

As a baseline for comparison, pin 16 of the FHC47 connector carrying data from your computer to the GPS should be idle except when trying to make a connection. This pin should be at a constant negative voltage like -5 or -6V DC when idle (and 0V AC).

If you do see 0V DC and AC on pin 9, then there might be a bad connection. You could test for this if you have a collection of resistors. You could connect something like a 1K ohm resistor between pin 17 and pin 9 and then measure the voltage on pin 9. If it then shows +5V, you have a break somewhere in the wiring to the GPS. If it still measures 0V, then either there is a short to ground or the GPS is outputting 0V per one of the conditions suggested above.

If this test indicates a break in the wiring, it might be worth taking off the front wheel to check on the GPS sensor and the wiring going to it.
 
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Dr No

Member
Mar 20, 2016
12
3
Austria
IMG_2310.jpg


Thank you for the Information!

First about the my problem: My GPS works, it shows the right direction the correct altitude but the wrong date (Sun 14 May) on my log file I could see that the car is in 2010 (could be there is no timeframe befor 2008).
So I know the unit is working, I didn use the oscilloscope because there was not enough time today.

With the multimeter I messured between 1 and 3.7V + and minus at DC and about 6V and higher with AC between Gnd and Rx Pin.
If I would realy have the GPS 18 do you know if a 18x would also work in my car?
If so, I would buy one and just change the GPS Unit (and find out wich one is realy in the car ;-) )

Thank you for your help!
 

slcasner

Active Member
Feb 20, 2011
1,172
789
Sunnyvale, CA
May 14 is the date we would expect for the GPS week-number rollover problem, but the year would be 2000, not 2010. When you look at the log file there would be some dates in 2010 because there is some permanently recorded information. But when you do the log file download, the filename should be something like 200005141234.tar which would indicate the year 2000.

The voltage measurements you made and the information on the display both indicate that the GPS is working, as you say. So you should be able to see the data with your computer. You don't need to use the SNSRXCFG program, you can use any program that allows showing data from the RS232 port in a terminal window. For example, I first looked at the data from my car using my MacBook Pro with a USB-RS233 adapter. Just make sure you get the RX pin of your computer hooked to the TX from the GPS, and set the baud rate to 4800.

Yes, a GPS 18x would work in a 1.5 Roadster, too. I don't know if the factory configuration of a new unit needs to be changed to fit what the car expects.
 

slcasner

Active Member
Feb 20, 2011
1,172
789
Sunnyvale, CA
Also, if you don't mind saying, what is the VIN of your car? I made an assumption that 1.5 cars had a GPS 18 whereas 2.x cars had GPS 18x, but yours appears to be a counterexample. I suppose it is possible that the sensor in your car failed and was replaced. Or perhaps the GPS 18 is also susceptible to this problem but has no firmware update to fix it.
 

Dr No

Member
Mar 20, 2016
12
3
Austria
Also, if you don't mind saying, what is the VIN of your car? I made an assumption that 1.5 cars had a GPS 18 whereas 2.x cars had GPS 18x, but yours appears to be a counterexample. I suppose it is possible that the sensor in your car failed and was replaced. Or perhaps the GPS 18 is also susceptible to this problem but has no firmware update to fix it.
IMG_2309.JPG
 

Dr No

Member
Mar 20, 2016
12
3
Austria
May 14 is the date we would expect for the GPS week-number rollover problem, but the year would be 2000, not 2010. When you look at the log file there would be some dates in 2010 because there is some permanently recorded information. But when you do the log file download, the filename should be something like 200005141234.tar which would indicate the year 2000.

The voltage measurements you made and the information on the display both indicate that the GPS is working, as you say. So you should be able to see the data with your computer. You don't need to use the SNSRXCFG program, you can use any program that allows showing data from the RS232 port in a terminal window. For example, I first looked at the data from my car using my MacBook Pro with a USB-RS233 adapter. Just make sure you get the RX pin of your computer hooked to the TX from the GPS, and set the baud rate to 4800.

Yes, a GPS 18x would work in a 1.5 Roadster, too. I don't know if the factory configuration of a new unit needs to be changed to fit what the car expects.

You are right: file name is: 200005071117.tar (last week),
As I found out, garmin does not support the GPS 18 any longer.
 

slcasner

Active Member
Feb 20, 2011
1,172
789
Sunnyvale, CA
I hope you are able to connect your computer to the GPS so we can learn if you have a GPS 18. If so, then those of us with early Roadsters will need to buy a GPS 18x.

My car was made two months before yours. Although it says San Carlos, that's really the date on which the computer was installed in the car on the assembly line in Hethel, England. I know that because I sat in it there a few days later.
IMG_5271.JPG
 

Dr No

Member
Mar 20, 2016
12
3
Austria
Screenshot 2019-12-30 18.26.58.png


Thats what I got from SNSRXCFG, I tried to set the baud rate to a higher level, because the Garmin update program starts with min. 9600 bps but it didn`t work.
 

slcasner

Active Member
Feb 20, 2011
1,172
789
Sunnyvale, CA
Thats what I got from SNSRXCFG, I tried to set the baud rate to a higher level, because the Garmin update program starts with min. 9600 bps but it didn`t work.
I assume that the configuration that you see there is just a set of defaults built into SNSRXCFG since if you have not been able to connect to the sensor yet it would not have had any way to pull the configuration from the sensor.

Or, if you are running the updater, does that mean you have connected successfully? If so, what version number does the PGRMT sentence show when you do View - NMEA Transmitted Sentences?

What I did for baud rate was to select 4800 baud manually in the dialog popped up by SNSRXCFG when doing the Config - Connect operation. Then when proceeding to the update step I selected Auto because 4800 was not listed in the dialog.
 

Dr No

Member
Mar 20, 2016
12
3
Austria
I assume that the configuration that you see there is just a set of defaults built into SNSRXCFG since if you have not been able to connect to the sensor yet it would not have had any way to pull the configuration from the sensor.
No, i could connect in the beginning, the Latitude, Longitude and Altidude are from my place, than I changed the parameter of the Baud rate.
 

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