The service manual does not, to my knowledge, list diagnostic codes that are only detectable by the dealer with CONSULT II and not detectable with other scan tools (called Generic Scan Tool or GST in the service manual). In fact, the heading at the top of the listing of Diagnostic Trouble Codes (DTC) in the Engine Control chapter in the service manual (EC), is titled both "CONSULT-II" and "GST". It may be that the dealer has the ability to retrieve code history, including the history of pending codes that never set off a CEL, that can't be read with other diagnostic readers.
All that said, you may be able to see a pending code if you connect a reader immediately after the truck cranks but fails to start and see a pending code that hasn't yet met, and apparently won't meet, in your case, the conditions required to to trigger a CEL.
Failing that, other possible causes (in no particular order):
1. Intermittently bad ground that's causing camshaft or crankshaft position sensor signal dropout. Remove, clean, and reinstall all ground connections to engine and chassis.
2. Bad connection in a connector camshaft or crankshaft position sensor. Remove, clean, and reinstall all cam and crank position sensor connectors.
3. Dirty or damaged camshaft or crankshaft position sensor. Remove, clean, and reinstall all cam and crank position sensors. Can also check the resistance between the three terminals on these sensors (1 to 2, 1 to 3, and 2 to 3); should not be 0 or infinite resistance.
4. Dirty or damaged camshaft signal plate. You may be able to inspect with a boiler mirror or borescope or may have to remove the valve covers.
5. Broken tooth or teeth on flywheel. Manually rotate engine and inspect flywheel through starter or crankshaft position sensor opening.
All that said, you may be able to see a pending code if you connect a reader immediately after the truck cranks but fails to start and see a pending code that hasn't yet met, and apparently won't meet, in your case, the conditions required to to trigger a CEL.
Failing that, other possible causes (in no particular order):
1. Intermittently bad ground that's causing camshaft or crankshaft position sensor signal dropout. Remove, clean, and reinstall all ground connections to engine and chassis.
2. Bad connection in a connector camshaft or crankshaft position sensor. Remove, clean, and reinstall all cam and crank position sensor connectors.
3. Dirty or damaged camshaft or crankshaft position sensor. Remove, clean, and reinstall all cam and crank position sensors. Can also check the resistance between the three terminals on these sensors (1 to 2, 1 to 3, and 2 to 3); should not be 0 or infinite resistance.
4. Dirty or damaged camshaft signal plate. You may be able to inspect with a boiler mirror or borescope or may have to remove the valve covers.
5. Broken tooth or teeth on flywheel. Manually rotate engine and inspect flywheel through starter or crankshaft position sensor opening.
