No Crank Reduced Power?

While driving 60 MPH, my engine stalled, the dashboard displayed Reduced Engine Power, then shutdown. Pulled to side of the road and would not re-start. Had to tow back.

The only OBD code was P0365, however, after extensive testing and replacement, I have figured the DTC showed-up because the camshaft is not moving. The exhaust camshaft sensor (CMP) is good/replaced and does not see the reluctor wheel spinning. Therefore, the P0365.

Outside of that, the only other OBD codes are related to my On Star system, which I do not use.

Unfortunately, I replaced the starter through great hassle. Poor GM design. Turns out I replaced a good starter with a new one.

In the process, I accidentally crushed the injector fuel harness, which had its looming completely deteriorated. Poor GM design. Had to take the intake manifold back off and rebuild the harness.

Re-installed the harness, re-installed the intake manifold, re-installed the throttle body and resonator. Everything back installed, no fuses blown and still the starter just spins.

What threw me off was the crankshaft sensor (CKP) was actually reading some RPM (around 160) while attempting to start. The flywheel was not turning, as it was guessed the false reading was coming from interference from the starter motor. All these are in close proximity.

The crankshaft will not turnover.

Oh, and through a fiber optic camera, discovered the timing chain was not thrown/broken.

Decided to change oil and filter while the truck was on floor jacks. No metal fragments in the old oil.

Where I am at now is the ignition switch is turned to start, the starter spins (I do not think the pinion gear is engaging the flywheel), and yet the truck does not start.

The battery is a few months old and has checked OK.

Something just tells me this is a ground issue, wiring issue, or somehow the ECM is stuck on Reduced Power Mode.

Have pulled both battery cables and shorted the two with jumper cables to load/drain any residual power in the system.

All lights and systems seem to work just fine. Just no cranking, though the starter spins.

The odd part of what I see in the dashboard display is a check engine light (CEL) and the mileage displayed. The only time I have seen just the mileage displayed is whenever I have disconnected the battery. Usually, I insert the key, turn to on and the tripometer is displayed. Have to manually push the switch to change to mileage. As if the ECM is stuck in a mode.

By the way, last year went through some issues and thought the ECM was bad. Ordered a new one and had it pre-programmed. Did not solve my issue at the time, which was a crankshaft position sensor. So, I returned the one I bought for a refund and re-installed the factory original ECM.

As a side note, my TPMS system was displaying Low Tire, meaning low tire pressure, and that no longer displays after this shutdown failure. The tire are properly inflated. All TPMS sensors are new, yet the on-board system just will not read the sensors. I just dealt the with warning dings when starting as an annoyance and just live with the problem. Not sure if any of that would prevent the truck from starting.

Cannot find anything remotely similar to what I am experiencing.

Any thoughts, help and advice are welcome.

– Stan