Simulate a route and see if you get the JCV or not. From Central rama 2 to the mall bangkae should be the easist to check.
Do you still get the thai menu? If so can you please share the th_TH.glx, th_TH_PRX.glx, th_TH_TRF.glx its in the /text folder of the device.
And the file 006-D0952-04.bin in the ./system/ExtData.