I cannot get left seat to go upright in 3rd row of Denali, -lever "1" is stuck. on 2003 GMC Yukon Denali

I often leave the third row of sears up and out of the way so I can have more storage space in the back, but I have never had this problem before. Please advise, - will dealer charge a lot for fixing this, and how will they do it?

Asked by for the 2003 GMC Yukon Denali
I had a problem similar to this when i worked at a Gm dealer. The cable had wore out and broke. To remove it I had to disassemble almost the entire seat while still in the vehicle. I hope this is not the problem but I have a bad feeling about it. Trace the cable from the level to the other end. Then operate the lever to see if you are getting the proper action from the mechanism. If it seems there is good movement then maybe its just stuck. If there seems to be no movement then the cable is broken. I didnt not handle the bill side but I believe it was at least a few hundred dollars.