Fernando, That Buick Must Be Out Of Warranty, Eh ? Otherwise You’d Just Take It In and Have It Fixed, Right ?
Check all the fuses, of course.
You will probably need to go someplace (dealer, other) that can scan Body DTCs (diagnostic trouble codes).
Buick has found that some 08 Enclaves and Cadillac DTSs with inoperative Power Tilt/Telescope and that reveal a DTC B2860 or B2880 need to have the Tilt/Telescope Position Sensor replaced, but that will need to be scanned and diagnosed. GM published a Technical Service Bulletin on this topic for their technicians.
The sensor (if needed) is now available as a separate part instead of only purchased with an entire steering column assembly.
Bad News: Sensor replacement labor is close to a couple hours.
Good News: This can be repaired, but will probably need to have Body DTCs scanned to determine what’s causing the problem.