Thank you for your response one is nuvi 3490 the other is nuvi 2350.
If I set the frequency in FM Traffic status , it starts receiving information but when I put it back to NORM it stops. But even though it receives the information it doesn't display it .Maybe there is a problem in TrafficProvider.xml, currently I have replaced 4.90 with 4.80.
But both nuvi-s with GTM36 are working without problems.