GPS time sync

[icu12345]

Peugeot 308 SW with RNEG unit. I checked the "synchronise time with GPS" checkbox in the time adjust menu.

As far as I could find out this is supposed to sync just the minutes, while the date and the hours have to always be adjusted manually.

Anyway, today at 7:30 am the clock was showing 7:28. I opened up the menu and the GPS sync was still checked. However, I could only adjust the clock manually to 7:26 or 7:41 and nothing in between.

So I unchecked the GPS sync and then I could adjust the time to anything I wanted so I could finally set the time correctly.

So is this normal? If so then the GPS synchronization should be somehow calibrated... How do I do that? Could someone shed some light on this? Thanks

[GiveMeABreak]

You need to be aware of the 'GPS N Week Rollover' issue.

The GPS satellites broadcast a date and a weekly counter that was only designed to be stored in 10 binary digits, providing a range of 0-1023. So every 1024 weeks or about 19.6 years, an integer overflow occurs resulting in an internal rollover. If your software can't deal with the change, it can lead to abnormal behaviour, including incorrect dates and times, route timing calculations etc. The last rollover occurred between 6th to 7th of April 2019.

The older GPS systems fitted to PSA cars including the MyWay could have issues with accuracy of route calculation and time / date settings, but these systems are no longer updated. The 'fix' in these cases is to remove / uncheck the tick from the 'Synchronise Date & Time with GPS' option.

This means you will have to change the daylight time changes yourself, but it should resolve any other issues you have.

[icu12345]

Thanks for pointing that out. Just out of curiosity, does the RT6 system have the same issue?

[GiveMeABreak]

Yes, those systems are no longer sold, so there are unlikely to be any new firmware updates. Newer systems like the Connected Nav should be fine.

[Paul-R]

The eMyWay (RT6) system in my X7 doesn't have the GPS synchronisation unticked and I don't suffer from any problems.

I did have a problem a couple of years ago when, after updating the maps, I was pestered to "Insert installation disc" and the car position was always to one side or the road I was using. Unticking was suggested but that made no difference. Another option was to reinstall the firmware (I was already on the latest 2.86) and I nearly did that. In the end installing the next issue of the maps solved the problem and I am now sure that it was a corrupted installation of the previous maps that was the problem. This was caused by switching off the ignition before an area had been fully updated and I now take extra care when updating maps.

So, no problem with my RT6 and, I suspect, probably all which have the latest firmware.

[icu12345]

So, no problem with my RT6 and, I suspect, probably all which have the latest firmware.

Maybe the RT System works better with the latest update available. I have already updated the RNEG FW to RNEG_R50b_R50.03 but this doesn't seem to solve it. I will play with it some more but I guess that there is no way around the issue except for unchecking the GPS sync...

[GiveMeABreak]

Please don’t cross threads. There is nothing similar with the RT6 Magneti Marelli units and the MyWay RNEG by Harman Becker.

Your time issues should be resolved by following the guidance I already provided above.

[icu12345]

Understood. Sorry

[GiveMeABreak]

It’s not an issue, but for the benefit of new or later members, we don’t want to be mixing problems with different Head units, which is why we have separate sub-forums for these.

RT4, RT5 and RT6 (eMyWay) units are made by Magneti Marelli
MyWay and NG4 Navidrive 3D Telematics units are made by Harman Becker

They all have different software and operating systems.

I mentioned the GPS N week rollover as a general issue - as it will affect different models in different ways, but more importantly the time issue should be resolved for you by unticking the box.