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

[inmypassatlife]

I remem my bil 97 malibu did this on my driveway i feel like it was something with the remote un locking the doors then locking again ... he had aftermarket keyless entry, not so much an alarm but just a remote fob for keyless but it went into theft passlock or someshit... just ideas

Yep, tried that too, I have the original fobs plus the aftermarket. Made zero difference.

 

[Alberta Tahoe]

I'll be interested in reading your results.
As for me, this is what I figure. If I can remove this engine and the complete wiring harness and drop it into another chassis, like my 86 Camaro for example, and get it to run as has been done literally thousands of times by others, then I should be able to get it to run in the original chassis.
I just have to keep looking, reading, testing and asking questions.
In the meantime, I'll probably be forced into buying a replacement (another Tahoe of the same generation) as I can't keep driving said 86 Camaro too much longer. Winter is almost here in these parts.

 

[inmypassatlife]

#1, make sure the ignition switch is indexed correctly. I figured this out over the weekend. Replace the switch and the ignition switch housing. The housimg is where the Passlock sensor is actually located.

#2, I ordered a new BCM from Amazon. It was $117, but they can be had for $72 after you return the core. I didn't want to wait 5 days for delivery so I went Amazon.

#3, get BCM reflashed with tech2.

#4, unplug cluster, wait 10mins, and plug back in.

#5, go through Passlock relearn procedure. Search for Cardone Passlock procedure PDF. Best one there is. Although our keys look like Passkey3 we have a Passlock2.

Mine fired up tonight and is working as it was intended.

 

[afpj]

Have you tried any of the pass lock bypass tricks? I googled gm pass lock bypass and found a few things, different depending on which pass lock system you have. This one was the simplest:

Others require wiring bypass in steering column etc.

 

[swathdiver]

If you join All Data DIY, you can access the wiring diagrams for your truck and just about everything else as well.

 

[Alberta Tahoe]

Have you tried any of the pass lock bypass tricks?

I can't even get that far. The dash isn't functioning as it should and hasn't since this (newest) problem started.

If you join All Data DIY, you can access the wiring diagrams for your truck and just about everything else as well.

Just checked that out. I've found a lot of wiring info on-line however I suspect I may have to go deeper and eventually pay for what I need. Looks like a promising web-site.
Thanks.

 

[inmypassatlife]

Have you unplugged the cluster for 10 minutes then plugged it back in, done the key relearn procedure? People think i am nuts, but even after a BCM reflash that is what worked for me and at least 3 other people on another board.

 

[Alberta Tahoe]

Have you unplugged the cluster for 10 minutes then plugged it back in, done the key relearn procedure?

#1, make sure the ignition switch is indexed correctly. I figured this out over the weekend. Replace the switch and the ignition switch housing. The housimg is where the Passlock sensor is actually located.

I've replaced the electrical portion of the switch however it's difficult to tell if it's indexed correctly. I can get full range of motion with the switch and reach the spring back portion of the start position however this does nothing with respect to starting. Still no crank nor is there a change in dash function as there usually is when the key is turned to start. (Gauges sweep back to zero, indicating lamps turn off while key is in start)

#2, I ordered a new BCM from Amazon. It was $117, but they can be had for $72 after you return the core. I didn't want to wait 5 days for delivery so I went Amazon.

Can't say if I have an issue with the BCM or not.

#3, get BCM reflashed with tech2.

Trying to arrange the loan of a Tech 2 scanner to see if it is of any assistance trouble shooting.

#4, unplug cluster, wait 10mins, and plug back in.

How is this done? I haven't researched it but I've nothing to lose by trying. Is this a connector and where is it located?

#5, go through Passlock relearn procedure. Search for Cardone Passlock procedure PDF. Best one there is. Although our keys look like Passkey3 we have a Passlock2.

Again, I can't say if this is my issue and to tell you the truth, I'm not certain how to tell if it is an issue. That said, again, I've got nothing to lose by trying.

Mine fired up tonight and is working as it was intended.

I'd like to be able to say the same thing.

 

[Alberta Tahoe]

Another update:
For whatever reason, I've regained full functionality of the dash instruments. I did nothing extraordinary except go away for two weeks. Now, when the key is first inserted, I get a door chime, tuned to the ACC position, I get the radio and power windows, the ON position makes the gauges do a full sweep. (I haven't seen that there was still a 3/4 tank of fuel since this whole deal started but now I do).
The only thing lacking is that when turned to the START position, nothing happens. Still.
And further to that, once the start is tried, the gauges stay on like before when the key is removed. I'm certain there is backfeed somewhere probably due to a bad ground. I cannot for the life of me figure out where this ground might be.
I'm going to investigate the Passkey reset. Perhaps I initiated something there with all of this fiddling around.
But, at least I can say it appears the ignition switch is not a problem. Or so it seems.

 

[swathdiver]

When is your Tech2 arriving?

 

[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?