2000 yukon xl transfer case control module clicking

[Rdb0u812]

Need help! Service 4wd light came on and clicking from the tccm, also all lights are on on my 2/4wd button. Even with the key out tccm is clicking. Sometimes I can start it up and shift to 4wd, eventally it acts up (service 4wd, lights and clicking) and I'm stuck in what ever 4hi or low or 2wd. I can let it sit and it will let me go to 2 wd. I am keeping the 15a 4wd fuse out to keep it from shifting. Somtimes even with the 15a 4wd fuse out tccm still clicks and 2/4wd buttons flash. Help. Please.