1 /5 Larry Lee: Did a repair service a couple months ago. There was diagnostic fee $135. Even you go with them for the service. They still charged me $135 diagnostic fee. And I was never told there was a diagnostic fee $135 even you Go with them for the service. If I had known there was a unwaverable diagnostic fee $135, I definitely would have gone to another GM dealership such as GM Hall at Tyler. If they do a diagnostic test and find problems but you choose NOT to do service with them, you will be charged a diagnostic fee. Try to avoid this dishonest GM dealership so that you can avoid their ripoff.