One night after a flash my center stack was completely dead.

I had to pull the fuse to reset it, maybe you can try that with the ECM.

More often than I think is acceptable I have had my HVAC have no functionality after a flash....I flash again and all is good....No idea if that's SCT or this ECU...I'd say about 1 in 20 flashes this happens to me

Quote from: FoMoCoSHO on August 06, 2016, 11:39:34 PM
What kind of OBD?

Sounds like it may have caused an issue.

I'd turn on the lights and pull the battery cable.

Let it sit for a while and reconnect.

A cantech. Cheapy harbor freight scanner. What kind of problems could a scanner have caused?  And whats with turning lights on first before disconnecting battery??

So i found these  https://youtu.be/pJBMgrW7MQU https://youtu.be/-y9sTr3F-xY. So i tried regrounding battery and will proceed to check voltage at pcm tomorrow.

Quote from: Flexthis2011EB on August 06, 2016, 11:59:01 PM

Quote from: FoMoCoSHO on August 06, 2016, 11:39:34 PM
What kind of OBD?

Sounds like it may have caused an issue.

I'd turn on the lights and pull the battery cable.

Let it sit for a while and reconnect.

A cantech. Cheapy harbor freight scanner. What kind of problems could a scanner have caused?  And whats with turning lights on first before disconnecting battery??

Full discharge.

In my experience the ECM seems to retain power for quite a while after battery pull.

Quote from: Flexthis2011EB on August 06, 2016, 11:59:01 PM

Quote from: FoMoCoSHO on August 06, 2016, 11:39:34 PM
What kind of OBD?

Sounds like it may have caused an issue.

I'd turn on the lights and pull the battery cable.

Let it sit for a while and reconnect.

A cantech. Cheapy harbor freight scanner. What kind of problems could a scanner have caused?  And whats with turning lights on first before disconnecting battery??

Cheap electronics can reap all kinds of havoc. Cooked ECM, shorting, corrupting the data stream, and even viruses can't be ruled out either since some of these chips can write data as well.

The Mrs says pull your PCM power relay and check it.

Quote from: AJP turbo on August 06, 2016, 11:51:32 PM
More often than I think is acceptable I have had my HVAC have no functionality after a flash....I flash again and all is good....No idea if that's SCT or this ECU...I'd say about 1 in 20 flashes this happens to me

I had mine read zero fuel and stumble and stutter like it was empty after a reflash.  Was reading zero miles to empty.

Several restarts later, it decided there was fuel in the tank and ran OK.  No idea why.

OP, good luck!  I think the general thing to take from this is to only plug into the OBD port when the car is off.  Not that you should have to do that, but these things seem to be finicky.

My best guess overall is that it's the PATS system that isn't happy.  Don't know what to do to reset it, but I would look at it as a possibility.

Anyone know how to tell if a bad pcm is the culprit. How can i test that?

Did you check your PCM power relay?

Yes, by switching it with relay next to it

I still stand by an Instrument Cluster/PATS problem.  Injectors won't fire if PATS does not recognize the key.  It's good that it's cranking over at least.  So I would disconnect the battery again with lights on (like FoMoCo instructed) to drain residual charge in the system.  Then try again. 

Preferably, make a video of what is going on once you try to start they car.  A video will convey so much more information, easily.

12.3V on the battery is on the lowish side.  I would get a digital load tester (like the solar BA5/BA7 - really nice units) and check CCAs. I don't believe the battery is the issue though at this point, just to be clear.

Quote from: SHOdded on August 07, 2016, 06:46:26 AM
I still stand by an Instrument Cluster/PATS problem.  Injectors won't fire if PATS does not recognize the key.  It's good that it's cranking over at least.  So I would disconnect the battery again with lights on (like FoMoCo instructed) to drain residual charge in the system.  Then try again. 

Preferably, make a video of what is going on once you try to start they car.  A video will convey so much more information, easily.

12.3V on the battery is on the lowish side.  I would get a digital load tester (like the solar BA5/BA7 - really nice units) and check CCAs. I don't believe the battery is the issue though at this point, just to be clear.

So if it is indeed the PATS system not recognizing the key, is bringing it into dealer the only fix? Do i have to tow car in there or can i get key without car being there? Also the car has been sitting with terminals off batt all night. Gonna go see if anything happens. Ill make video.

Do you have an X4?

If so you can plug it in and grab codes.

No x4. Just standard code readers.