My '09 SS (LNF) w/ about 120k miles has been out of commission for a few weeks now as I try to track down the problem with no luck so far. The short version is that it's running extremely rough to the point where I'm not willing to drive it and it's throwing P0016 and P0017 codes saying the intake and exhaust cams are both too far out of sync with the crank. I also get "no data" for the intake and exhaust cam angles on the RPD screen. Last time I started it the battery light on the dash was also on.

Full story:
Went out for lunch, car drove completely normally. Went to go out again about 3 hours later, car started normally and I got about halfway backed out of the driveway when the engine stumbled and stalled. Turned the key off, restarted it, stumbled and stalled again. Tried to restart again and I got nothing, wouldn't even engage the starter. Tried once or twice more and still got nothing, so I plugged in my code reader and it wasn't able to connect. I was also getting a message on the dash about power steering with the CEL blinking rapidly. After checking a few things under the hood I found that the fuse for the ECM was blown. I replaced that and was able to connect my code reader and I got P2105 (Throttle Actuator Control System - Forced Engine Shutdown) and P2090 (B Camshaft Position Actuator Control Circuit Low Bank 1).

After replacing that fuse the car actually started but was running extremely rough and was struggling to idle. As I said above, I was getting "no data" on the display for the cam angles and the battery light on the dash was on (the RPD showed about 14v for the battery). Ran the car basically just long enough to get it in the garage and checked the codes again and found P0016 and P0017 as the only codes. The battery had been unplugged for a while which probably reset the other two.

From what I've been able to research so far, the likely culprits are the timing chain, crankshaft position sensor, camshaft position sensor(s), a bad ground somewhere, and/or the ECM itself. I'm a little worried about the ECM since that fuse blew, really don't know what would cause that. I've checked every ground in the engine compartment that I can find and they all seem ok, no real corrosion or loose connections. I don't think the cam sensors are the problem since the odds of them both going out at the exact same time are pretty low.

So far I've tested the crank position sensor and it seems to be working. I'm getting about 4.9v to the sensor with the ignition on. The signal wire measured 0.7v with no metal in front of it and switches to about 4.9v when touched with a wrench. I'm not 100% sure what these values are supposed to be, but the fact that it was reacting to metal and switching between high/low voltage makes me think it's OK.

I've also taken the valve cover off and checked the top end of the timing chain and the upper guide which I've seen several threads on, both of which seem to be fine. I'm still worried there could be something wrong at the crank end of the chain, checking that may be my next step unless someone here knows of a more likely solution or easier test.

Any suggestions are welcome!