my truck just died yesterday (july 3 07) with codes 1688,1689 1693, the ip was replaced ...... truck runs good now.all codes were removed and haven't returned, the heating grid code was also present (0380). as the result of my ip failure i believe lubricty or low fuel pressure has nothing to do with the ip control module failure.... the control module on the pump was the problem.
probably the mechanical part is still good, i had good lp pressure, and 2 stroke oil in my tank
but it still failed
i was ready to leave the truck until thursday or even monday but didn't have to.

by the way, industrial injection in salt lake city furnished the pump and labor , i think they went out of their way to get me going! many thanks to bart timothy ( he trailered my truck to industrial injection's facility). also i want to thank the guys at ind.inj. for the fast service. i was "on the road" at about 6:30 pm....... thank's again guys!!