Have you got access to pathfinder? Making sure that both steering sensors are calibrated correctly is the first thing to try.

If that doesn't do the trick, have you got another truck that you could swap The Lord unit over with? These are expensive so would be worth seeing if the fault transfers.

There have been problems with the wiring looms, test the resistance between plug 3x4 (Saab plug under the dash, near the footwell) and plug x/50L (right hand can plug on the steer motor/module) anything over roughly 0.5amps then the loom will need repairing. When the trucks are built the loom arrives in two pieces and is crimped together, excessive resistance in the crimped connections causes this fault.

Hope this helps :)