GPS 12 wrong date Garmin

ben · Oct 13, 2015

I know most of you have moved on from the garmin GPS 12 none the less I powered my two 12's up only to discover the "Date Problem". Have tried the resets and no change. Can Anyone help?

Nuvi-Nebie · Oct 13, 2015

This sounds like the EOW counter problem, the time / date data sent from the satellites to your GPS is contained in two registers, one counts seconds and the other counts weeks, when the seconds counter gets to the end of a week, it increments the week counter and resets to zero. Originally the week counter only had 10 bits in it so it could only count 1024 weeks (about 20 years) before it resets. The counters started from January 6, 1980 so they went back to zero on August 22, 1999. In later models the week counter was increased to 13 bits so the problem won't occur for 150+ years but that won't help the old models because they can only use 10 bits. Because of the End Of Week counter problem, old units must have a current date no more than 10 years away from the real date, if they don't, they will never display the real date. One fix for this is to set the unit back to factory default, I'm guessing that your 'resets' was doing this, it usually take the form of :-

1 Switch off
2 Press MARK and power on together.
3 When it says "do you wish to delete data" it should default to YES.
4 Switch it to NO,
5 then switch it back to YES,
6 then switch it back to NO,
7 then switch it back to YES
8 finally press ENTER

After the above it will take some time to find satellites again because the unit will 'Cold Start' (no almanac, time, position etc.), if the time remains unchanged or is more than 10 years in the past or the future, there is only one other fix I know of, it involves downloading a GpsEow.exe program onto a computer that is connected to your GPS12 via an RS232 com port, this program will send a new date to your device. I have used this program on a GPS38 unit and it did install a new date that was roughly 1 year into the future, but I have no knowledge about whether it work on a GPS12

Alastair Mackenzie · Oct 15, 2015

Hi there, I have recently sorted the Eow date problem using the Eow software on a Garmin 12XL so I am sure it will work just fine on a Garmin 12. You will need an old pc running Windows XP with a 9 pin serial port and a Garmin computer connection lead. All you need to do is :-

(1).Download and install the GpsEow software and install on a Windows XP computer.
(2.) Open the software on the PC.
(3.) Connect the GPS to the computer using the serial port.
(4.) Switch on the GPS and make sure the interface setting is set to Garmin to Garmin.
(5.) On the computer screen - click on the Upload time button.
(6.) A message will appear on the computer screen confirming that the time has been uploaded.
(7.) Switch off the GPS and disconnect lead. Switch back on.
(8.) Go to the date page where you should find the date is now incorrect but some date in 2016.
(9.) Take the unit outside where there is a good view of the sky. It should pick up the satellites and as soon as it gets a 3d fix (minimum 4 satellites) the date will be corrected to the correct time and date.

Hope this helps you out. If you need a link to the GpsEow software let me know.

N.B. Don't forget to change the GPS interface back to NMEA if you need the GPS to talk to a data logger.

mlaajanen · Mar 13, 2016

Hi

Just downloaded the program to fix the week problem which causes by 12XL to stay on 1996 and now it is back on track

And the best wityh GPS12 is its current consumption, 50mA at 12VDC is really great in sailing boat

Wish there where some way to fix the small isues with the LCD display aswell!!

Thanks Nuvu-Nebie!

says 2016

Simon Templar · Mar 16, 2016

No surprise.....once again, us Mac types are left out in the pre-Y2K cold.

....sT

Roger P. · Nov 10, 2020

Alastair Mackenzie said:
Hi there, I have recently sorted the Eow date problem using the Eow software on a Garmin 12XL so I am sure it will work just fine on a Garmin 12. You will need an old pc running Windows XP with a 9 pin serial port and a Garmin computer connection lead. All you need to do is :-

(1).Download and install the GpsEow software and install on a Windows XP computer.
(2.) Open the software on the PC.
(3.) Connect the GPS to the computer using the serial port.
(4.) Switch on the GPS and make sure the interface setting is set to Garmin to Garmin.
(5.) On the computer screen - click on the Upload time button.
(6.) A message will appear on the computer screen confirming that the time has been uploaded.
(7.) Switch off the GPS and disconnect lead. Switch back on.
(8.) Go to the date page where you should find the date is now incorrect but some date in 2016.
(9.) Take the unit outside where there is a good view of the sky. It should pick up the satellites and as soon as it gets a 3d fix (minimum 4 satellites) the date will be corrected to the correct time and date.

Hope this helps you out. If you need a link to the GpsEow software let me know.

N.B. Don't forget to change the GPS interface back to NMEA if you need the GPS to talk to a data logger.

Hi Alistair - Can you send me that link to get the GpsEow software? Thanks.

Nuvi-Nebie · Nov 10, 2020

You might not get a reply from Alastair as his post is was 5 years ago, I have made a forum page for the rollover fix, it has the file you are looking for at the bottom the page :-
https://www.gps-forums.com/threads/what-is-the-week-rollover-problem.46549/

Alastair Mackenzie · Nov 10, 2020

Roger P. said:
Hi Alistair - Can you send me that link to get the GpsEow software? Thanks.

Hi there, I think someone else has posted a link to the software just now. To use it successfully you need to have installed a new internal memory battery first. Obviously you also need a Garmin serial port lead as well. If you have both, you can proceed with the software. Dont be surprised if the software doesnt correct the date exactly when you use it. If the year is right it will correct itself as soon as it gets a 4 position 3d fix from the satellites. After that, give it some time outside with a good view of the sky to download a new almanac of satellite data. This will be stored and make position acquisition faster in future. From memory, other data may also be lost - something to do with temperature compensation from memory but I believe it restores itself over time with use.
Hope this helps. Can I assume you have managed to identify the memory backup battery and renew it okay? This is the tricky part for sure.

Kind regards,
Alastair.

Roger P. · Nov 16, 2020

Alastair Mackenzie said:
Hi there, I think someone else has posted a link to the software just now. To use it successfully you need to have installed a new internal memory battery first. Obviously you also need a Garmin serial port lead as well. If you have both, you can proceed with the software. Dont be surprised if the software doesnt correct the date exactly when you use it. If the year is right it will correct itself as soon as it gets a 4 position 3d fix from the satellites. After that, give it some time outside with a good view of the sky to download a new almanac of satellite data. This will be stored and make position acquisition faster in future. From memory, other data may also be lost - something to do with temperature compensation from memory but I believe it restores itself over time with use.
Hope this helps. Can I assume you have managed to identify the memory backup battery and renew it okay? This is the tricky part for sure.

Kind regards,
Alastair.

Thanks Alistair and Nuvi-Nebie,

I have managed to charge the internal memory enough that I don't get the "Memory Battery is Low" message. I've loaded the time in it and it's now searching for satellites. Thanks for the help. I've been using a Garmin 78s for years now, and came across the old 12XL while cleaning up a bit. I used it alongside the 78s as well as my mobile phone GPS, for a short walk in the bush (woods) behind our house. The accuracy of the 12XL compares well with the 78s, but unfortunately it just can't see the satellites under minimal amounts of forest cover, and noticeably worsens when heavy overcast sky is added. So I'm trying to correct the date just for the exercise. Thanks again for your help. Stay safe and stay healthy, Roger P. Mulligan.

Roger P. · Nov 17, 2020

The GpsEow.exe worked. Once I set the time offset to -5 hours, the 12XL showed the correct time and date. However, when I mark a waypoint, go to the waypoint list, the time shows as GMT. I've left it on for the night to see if it can adjust itself. Thanks for all the help!

Cheers, Roger.

Nuvi-Nebie · Nov 17, 2020

I think you are referring to the 'Waypoint Comment', see below :-

This can be changed, but the default is the Time / Date that the waypoint was created, note that the Time is always in UTC = GMT