Have two older TomTom 520 units (because the memory at 4mb each) was too small to contain maps required.
TomTom have emailed this advice in recent days:
Due to the upcoming WNRO on
6 April 2019, the performance of your device will be impacted.
While we no longer offer content and service updates for your device, we have made an update available that addresses the GPS Week Number Rollover (WNRO).
TO UPDATE: Connect your device to your computer. Click the
‘update now’ button for instructions on how to update your device.
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Check your satnav's status
Your satnav has always been there to guide you, now it needs your help.
On
6 April 2019, the
GPS Week Number Rollover may impact your satnav. Please connect your satnav to your computer to check if you have the latest software version. If you do not already have MyDrive Connect or TomTom Home on your computer, we are here to guide you through the next steps. Get started by entering your serial number below.
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The GPS Week Number Rollover (WNRO) occurs every 19 years, with the next roll over taking place on 6 April 2019. Similar to odometers in older cars rolling over from 99,999 km to 0, the GPS WNRO is the resetting of the GPS calendar back to 0.
When the calendar resets, it can cause a miscommunication between GPS satellites and GPS receiver chips. As a result, some chips in satnavs will lose the ability to process certain functions.
What does this mean for you? It’s time to check your satnav. Depending on your device, you may need to update or upgrade.