GMC Repair: GMC ignition switch or Passlock II issue?!, gmc sierra, case assembly

Question
2003 GMC Sierra 5.3L v8 70000 miles - Hello! Driving down highway truck just quit like someone turned the key off. Engine will not turn over.Starter tested and found to be be good. Battery,fuses,wiring all ok.Have all lights etc. and power to starter. Tested starter with mechanics remote and starter turned but truck would not start.Passlock? will not turn over with key switch. Passlock light flashing on dash. I cant figure it out!Tried resetting passlock, but no go. Bad Ignition switch or passlock II problem ?? I hope you can help me with this, nobody else seems to be able to. Dealer wants huge $ and I cant afford it. Thanks!  

Answer
Hi
To diagnose Passlock III system on this vehicle we'll need to retrieve codes from VTD system (BCM). If you know ANYBODY with a scan tool that'll scan truck for you and get codes, I'll be WAY more than happy to assist in diagnosis.
I can tell you from experience with the Passlock lamp flashing, that is your problem. I can also almost tell you it will probabally need the Ignition Lock Cylinder case assembly. This houses the PasslockIII sensor.
BUT before you spend this $$$$$$$   you REALLY need to have the BCM and PCM scanned for codes to run diagnosis for those codes. As I stated, I'll be MORE than happy to assist in that diagnosis, if possible.
Please follow post back.
Pawl