Has the satellite icon/symbol on your Renault GPS satellite navigation sat nav screen turned from green to red? This likely means that the signal has been lost due to the aerial going bad perhaps due to water ingress, or because of the lead from the antenna aerial into the back of your shark fin sat nav aerial on the roof. If so, you might want to try replacing the sharkfin black plastic roof arial, and/or the actual lead/wiring, to see if it turns your satellite icon from red back to green again?
Here's the link for the GPS aerial on eBay currently as of today http://cgi.ebay.co.uk/ws/eBayI…..0661736861
This applies to Renault cars with the Carminat sat nav system, which is VDO Dayton based and uses Navteq discs in most cases. It's not for the CNI2 (Carminat Navigation Informee 2) systems, we don't think.