No crank/start/anything condition with radio also in locked mode.

[Alberta Tahoe]

When is your Tech2 arriving?

I found a local technician that has a loan of one. It'll be whenever he gets over to my place. Hopefully in the next day or so.
A further update: When attempting to do a Passkey recovery, the dash function doesn't stay on long enough. While the initial turn to the ON position results in the expecting sweep of the gauges, after about a minute or so, it all drops out. There is obviously still a problem with the wiring or the components connected to it.

 

[inmypassatlife]

remove 4-7mm screws that hold the cluster in, remove it, remove the connection at the top, then reverse the steps i listed and turn the key on, see what the cluster does.

 

[retiredsparky]

For $40 or less you can sign up at Alldatadiy.com for 5 years. The drawings clearly show that the ignition switch sends 12 V+ (fuse labeled IGN A) to the PCM in the start mode. The PCM then provides the ground for the start enable relay. The start enable relay then sends 12V+ to the starter solenoid.

My point is that besides whatever other problems you have with your dash, you need to just look at the cranking problem first. Is the PCM getting the 12 V+ signal? Is the start enable relay getting the ground signal? Does the start enable relay get the 12 V+?

 

[Alberta Tahoe]

I haven't worked on the tuck much (if at all) over the past few weeks as I've been away however I do have something interesting to report.
For whatever reason, the last time I went about my normal testing routine, which is really not much more than inserting the key, the gauges all came back to life. Turning the key to the "on" position prompted the gauges to do a full sweep and provide accurate information. This is the first time the fuel gauge has indicated that I had 3/4 of a tank of fuel since this whole debacle started. Nothing was changed other than letting the truck sit for a couple of weeks. The battery has always been on a trickle charger and has always had a full charge.
Now just as interestingly, turning the key to start, still does not initiate the cranking cycle and the gauges then return back to their non-functioning state. Disconnecting the battery, will sometimes result in the gauges functioning properly but not always.
This indicates to me that the ignition switch is indexed properly and it's functioning as it should.
While I haven't tried the test posted above (gauge cluster), I will give that a go (another variable out of the way if at worst it has no effect) but I think the problem is in the grounding portion of the PCM.
I need wiring diagrams. I'll have to check out all of the links provided here.

 

[Alberta Tahoe]

Where is the best resource to find all of the locations for the grounding circuits for the PCM?
I've checked the usual websites and online sources however most seem available by subscription. Anyone have any links? Maybe there's a specific OEM manual other than buying the entire set of books?
I'm still troubleshooting the no start condition and am fairly certain it has to do with a poor ground from the PCM to the chassis. As posted above, I've found a few already just by nosing around and with some directions via the replies but from what I can tell, there might be a dozen more locations to investigate.
Any help is greatly appreciated.

As I mentioned in the previous post, after being away for a couple of weeks and then resuming the troubleshooting, the dash came back to life with the key in the "run" position. On it's own with no fiddling on my part. That was short-lived however and everything went back to being non-functional again.
I'm back to testing this week coming.

 

[inmypassatlife]

Where is the best resource to find all of the locations for the grounding circuits for the PCM?
I've checked the usual websites and online sources however most seem available by subscription. Anyone have any links? Maybe there's a specific OEM manual other than buying the entire set of books?
I'm still troubleshooting the no start condition and am fairly certain it has to do with a poor ground from the PCM to the chassis. As posted above, I've found a few already just by nosing around and with some directions via the replies but from what I can tell, there might be a dozen more locations to investigate.
Any help is greatly appreciated.

As I mentioned in the previous post, after being away for a couple of weeks and then resuming the troubleshooting, the dash came back to life with the key in the "run" position. On it's own with no fiddling on my part. That was short-lived however and everything went back to being non-functional again.
I'm back to testing this week coming.

Had this passkey issue again, it was the ground from the firewall to the underhood light

 

[Alberta Tahoe]

Had this passkey issue again, it was the ground from the firewall to the underhood light

Are you saying that the underhood light ground kept your vehicle from starting?!

 

[inmypassatlife]

Are you saying that the underhood light ground kept your vehicle from starting?!

Exactly what in saying, had battery light and security flashing intermittently. Found that ground had broken off and replaced it, removed both Ecm fuses and Tbc fuse and reinserted and boom, truck cranked and stayed on

 

[Alberta Tahoe]

Go figure. I'd never suspect something as benign as a light ground to be a source of trouble like that. It's no wonder my truck is dead. Of the dozens of ground connections, I can imagine that more than a few of them are in poor condition.
I've picked up a Tech 2 scanner but still have to get outside and spend more time on the heap. (Still pretty cold up here). Scanner notwithstanding, I'm guessing I'll have to find and inspect each and every connection on the chassis. Plus I'll have to investigate the passkey/VATS. The pre-existing intermittent short/open issue (which was at the very start of this fiasco) has probably been compounded by the fact that I've replaced the electrical portion of the ignition switch.

... had battery light and security flashing intermittently.

A symptom I don't have though.

 

[inmypassatlife]

Go figure. I'd never suspect something as benign as a light ground to be a source of trouble like that. It's no wonder my truck is dead. Of the dozens of ground connections, I can imagine that more than a few of them are in poor condition.
I've picked up a Tech 2 scanner but still have to get outside and spend more time on the heap. (Still pretty cold up here). Scanner notwithstanding, I'm guessing I'll have to find and inspect each and every connection on the chassis. Plus I'll have to investigate the passkey/VATS. The pre-existing intermittent short/open issue (which was at the very start of this fiasco) has probably been compounded by the fact that I've replaced the electrical portion of the ignition switch.



A symptom I don't have though.

Did you ever get it to start? What fixed it?