Keith,
Do you have manual or electric hydraulic control valve. The electric control valve would be controlled by finger switches mounted beside the seat. Manual would have long handles coming out of the dash on the right side. Electric hydraulics could be just a calibration of the mini lever or a failed mini lever. Some models you can swap levers from lift to tilt. To calibrate the mini lever will require access to diagnostics. For the manual hydraulic system, check the valve handle mounting, make sure nothing is loose or missing. I have seen the linkage still in place, but barely moves the valve due to loose linkage.
El control hidráulico es manual o electro hidráulico?