2003 Chevy Tahoe Auto Air Ride

Had a message come up to service auto suspension. I had a GM tech check the Tahoe and he found a bad right rear shock. It had to many ohms. We replaced both rear shock with GM replacements. The repair code is gone. Before changing the shocks it aired the back shocks way up. The suspension still will not level and the rear come back down. I even took the air lines off the new shocks. The susoension will not lower in the rear and I think the front is ip as well. Any suggestions?