Nuvi 765t - "Cannot calculate the route." happened after update of FW and/or Maps

**pitruchio** · 28th November 2011, 02:24 PM

There are no 'critical' maps. Delete them all.

**fpz** · 25th February 2012, 05:05 AM

I am having a similar problem after updating the firmware from 4.30 to 4.40 in a Nuvi 755. I cannot calculate routes for locations outside the US 48CONUSA. I have tried to calculate some routes in Panama (between two locations) using the SouthAmerica 2012.40 map and I cannot do it. However, I can calculate routes within the USA using the NorthAmerica 2012.40. Before the upgrade I was able to calculate routes without any problem using different maps. I have tried many of the suggestions mentioned before (re-installing maps and different versions of the firmware) but it is not working. This is a puzzling question that I would love to understand and maybe solve.

EDIT:
As I said in a previous posting, I had the same problem after updating the firmware to 4.40. I contacted Garmin and they made a lot of recommendations but I could not solve the problem. I am TomTom user (I do prefer the TomTom GPS since it is more "user-friendly") but I have a Nuvi Garmin (755t) that I use when I travel to places where I cannot use the TomTom.

I spent about a week dealing intensively with this problem and doing many things without being able to solve the issue. I was convinced that something got corrupted when I did the update and the problem was to find what file (or files). After many deletions and changes I think I found the source of the problem. The original NorthAmerican maps (both the regular and the 3d) plus the JCV were corrupted. I deleted all the img files and all the JCV files and I only kept one map (the one I will be using in Panama) and it is working again. I renamed that map from GMAPSUPP.IMG to GMAPPROM.IMG and now it is working fine. I can calculate routes in Panama and do all the things that I could not do before
like creating custom routes in advance.

As I said, I am not an expert on Garmin software or hardware and I solved the problem I had by trial and error until I found the source of the problem.

**chadiln** · 29th May 2012, 02:03 AM

Hi,

I am not sure if the OP had solved this, FWIW I had a friend with a similar problem on his Nuvi.

I was able to solve this by loading the appropriate Basemap on to the unit.

Hope this would solve it for you.

Chad

changa8km · 29th May 2012, 07:34 AM

hello peoples , this proq worked in sp 2 ?

**dasilvarsa** · 29th May 2012, 07:38 AM

Maybe some corruption on Nuvi Internal Drive or Memory Card ?
Maybe a corrupt file ?
Maybe a corrupt Flash Region ? (Not so easy to fix)

**StefanSchm** · 6th September 2015, 04:25 PM

Perhaps someone can help me out, too,

I updated my garmin 765T unit. New firmware (v4.50), new Maps (For example Garmin City Navigator Europa NTU Unl*** for 2013, 2014, 2015, 2016 as gmapsupp.img), basemap 501 and removed the old gmapprom.img.

I even tried older firmware versions 3.60 and 3.90.

The problem is, route calculation works until 99%. Then it says "cannot calculate the route."

What I've also done was updating the TMC Messages for Germany. It is really weird. All the necessary files should be in there. I even tried it with a sd-card. Attached you find the current file-structure.

I realized, that when I open the map with my unit, everything works quite slow. Zomming out takes ages. Route calculation is not possible for locations within the same town.

Thank you for your support.

**lolypop000** · 6th September 2015, 04:39 PM

How much is your free memory on your unit?
If you have less then 100Mb or GPX folder larger then 20Mb, then here is your problem.

Do you create hard reset?