I've recently puchased a (Canadian) 97 1/2T Silverado 6.5L at an auction. 121000 mi. Now you understand why it was at the auction. I didn't - I'm a diesel newbie - ignorant of 120000 mi warranties. I've also never done a forum before, nonetheless - I'll proceed. When driving the vehicle home from the auction I noted the RPMs seemed excessive - 2200 for 60 MPH. The error codes were 118, 223, 236,380, & 405. Took it into the dealership - reported 12 severed (Cleanly) wires going into the PCM behind the glove box and spliced all - engine ran intermittantly and spat out codes 223, 251, 370, 380, & 405. They finally cleared those, got it to run - markedly improved performance and stated they believed the EGR passages should be cleaned and the fuel filter should be replaced as the lift pump pressure 'appeared low'. Picked it up from the dealership and it stalled driving off the lot....... and numerous times since - both under load and going uphill. I've changed the filter and checked the lift pump pressure - 4.5 psi. Since becoming a member yesterday I've read with rapt interest the voluminous message traffic irt this subject - stalling. I took the vehicle back to the dealer and asked them to investigate the stalling and steered them towards the FSD. They insist on revisting the PCM harness and may perhaps work there way over to the FSD. Seems a plausible approach given someone had destroyed the harness and it IS possible a connector or conductor is degraded .....but all your postings about the FSD are very compelling - will update when known.

IRT the SOL-D product - as a supervisory electrical design engineer for the US Navy I can't over-emphasize the importance in 1st article testing of components that are to be placed in service in mission critical systems - whether it's the propulsion system on a nuclear aircraft carrier or your vehcile carrying your wife and children through a blizzard or across the desert - it had better be 'proven'. One observation from the SOL-D feedback comments is that the suspect diode was rated for 150 C - is that rise above ambient - or - absolute ? If ambient - what does your specification state as ambient ? Doesn't encapsulating the diode degrade it's thermal properties by trapping the dissipated heat ? I applaud this type of after market platform (SOL-D) and it's premise of attempting to improve/replace an OEM product - and I may ultimately install one as my confidence level in my dealership is waning - but I don't desire to be a participant (at my expense) in the test phase twice (dealership and SOL-D).
Having said all this - anyone ever encounter similar issues - ie cut harnesses ? My bet is the previous owner astutely determined how to bypass the PCM and keep it running (degraded performance) and once > 120000 - took it to the auction.
thanks