Service stability warning comes on for the autoride system

This causes the rear brakes to close as if the parking brake was engaged their is an override button to bypass stability control that only worked once I have disconnected the battery to reset it did help but problem returned. I have checked all fuses they check out ok, I was told to replace the ALC automatic leveling control relay but I just cannot seem to locate in the engine compartment I looked for it in the fuse box in the engine compartment no luck, I also checked for air leaks I cannot hear any air escaping from air lines leading to air shocks

Jorge