98 K2500 Suburban won't stay running.

AyWoSch Motors

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Maybe. Sometimes tough to tell from how people state it. I can see how one might read his post either way. Sounded to me like it's not as consistent behavior as I'd expect Passlock to be. Either way he's armed with next steps in troubleshooting. :)

Richard
Sometimes itll start for just a second, a little vroom and then die. Then every couple of tries itll start and run for about 2 or 3seconds, then die.

I'm working on both. If I can cheak the fuel pressure with a tire gauge, I can totally do that. And as soon as I get a few minutes I'll do the passlock relearn thing.
On that note, my key and lock cylinder are out of a 97 and this truck is a 98 or 99, is that gonna cause an issue. My key doesn't have a chip or anything in it I'm pretty sure.
 

someotherguy

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On that note, my key and lock cylinder are out of a 97 and this truck is a 98 or 99, is that gonna cause an issue. My key doesn't have a chip or anything in it I'm pretty sure.
There's no "chip" in the key as has already been mentioned. It's in the tumbler. This situation was created when you installed the wrong tumbler in the column.

Also helps to not guess what year the truck is - confirm via VIN 10th digit, because it matters. 1998 is first year for Passlock. 1997 does not have it and the tumbler will not work with the Passlock system.

Don't feel bad.. many of us have been there. My first experience with Passlock was on a '99 parts truck I was trying to get running and didn't have the key, so I swapped a tumbler, too - and the bulb for the SECURITY light was burned out already so I didn't even get that warning. :D

Richard
 

AyWoSch Motors

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There's no "chip" in the key as has already been mentioned. It's in the tumbler. This situation was created when you installed the wrong tumbler in the column.

Also helps to not guess what year the truck is - confirm via VIN 10th digit, because it matters. 1998 is first year for Passlock. 1997 does not have it and the tumbler will not work with the Passlock system.

Don't feel bad.. many of us have been there. My first experience with Passlock was on a '99 parts truck I was trying to get running and didn't have the key, so I swapped a tumbler, too - and the bulb for the SECURITY light was burned out already so I didn't even get that warning. :D

Richard
Ah, there's my issue. See I have a 97 parts truck cab too, that had a good column with cylinder and keys, and I thought why spend money when I already had the part. Figured it wouldnt changed one year to another, but I guessed wrong lol.

And I thought 98, because my title and the lot listing at the auction both said 98, but my bill of sale and the owners manual in the glove box both say 99, so in not sure. I'll decode the vin later, and find out for sure

So your saying I'll never get the truck to recongnise the key because the tumbler is the wrong yea, so I'll have to go buy a tumbler for a 98 or 99, or whatever it is, and itll work? Then I can do the relearn thing?

Now si ce you've told me what that is, I've looked it up a little to see other ways of fixing it. Theres a bunch of different hacks to make it run, but they all sort of involve "repairing" it. Is there anyway to just get rid of it or bypass it, like just unplug it, or cut it out and jump a wire sort of thing, or would the computer have a panic attack?

I'm a lot more familiar with eailer 90s chevys than I am the late 90s one, but I'm even more familiar with 73-87s, so the whole computerized everything thing is a whole another world to me. Sorry for my ignorance towards technology, haha. I'm learning... slowly...
 

df2x4

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Is there anyway to just get rid of it or bypass it, like just unplug it, or cut it out and jump a wire sort of thing, or would the computer have a panic attack?

The real solution is disabling it entirely in the tune. Takes specific software (JET Dynamic Spectrum Tuner, HPTuners, or EFILive, maybe others?) for a '98+, most places with the appropriate software will charge a couple hundred dollars to do it. Anything else is just fooling the system into working.

Black Bear Performance can disable PassLock in your tune if you mail them your PCM, I know a few other places can do it this way also.
 

HotWheelsBurban

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I went through this with my 99 Burb a few years ago. Getting the passlock deleted in the computer is the ONLY sure way to make that problem stop. I tried all the relearn procedures and they would work a couple times....then back to square one. That is the issue that got me introduced to this forum!
 

AyWoSch Motors

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The real solution is disabling it entirely in the tune. Takes specific software (JET Dynamic Spectrum Tuner, HPTuners, or EFILive, maybe others?) for a '98+, most places with the appropriate software will charge a couple hundred dollars to do it. Anything else is just fooling the system into working.

Black Bear Performance can disable PassLock in your tune if you mail them your PCM, I know a few other places can do it this way also.
I have access to lots of different parts trucks and junkyards, is there anyway I could swap the computer for one from a 96 or a 97 and put it in there instead, or is that just impossible?

I also have an 01 2500 suburban (still GMT400) that runs, but doesnt run well, and the whole thing has electrical gremlins big time because it was in a river for a few days. Could I potentially swap the computer or security parts out of that truck?

I sorta dont want to spend a "few hundred bucks" on it, I only spent a "few hundred buck" on it in the first place, and I'mnot totally sure its 100% healthy.
Plus theres no place around here that would do anything like that, so I'd probably have to drive 150 miles to Albuquerque, and I guess thatd require removing the ECM or PCM or VCM or YMCA or whatever its called out of it. Dont really want to do that. Guess I'll just replace the key cylinder and hope that does it. Either that, or I'll rip all that junk off and put a carb intake on it and an edelbrock and be done with all that. If that's even possible.
 

618 Syndicate

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Until you address the passlock issue it will never run. You can try replacing the cylinder, but swapping for a different year computer won't do it.
Also, an 01 suburban is not a GMT 400.
 

AyWoSch Motors

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Also, an 01 suburban is not a GMT 400.
Yes, I know that sounds weird, and I know better, because my boss had an 01 burb that was GMT800 as it should be, but trust me, this one isnt. Vin and title says it's an 01, but look...
You must be registered for see images attach

I can take a pic of the vin if ya dont believe me, but it checks out.
I think its because it's a Cheyenne not a Silverado.
 

618 Syndicate

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Then those aren't the VIN and title to that truck. 99 was the last year of the 400 Burbs, has nothing to do with the trim level.
 

mattillac

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Here are a couple links to have just the passlock tuned out, the ebay one is under 100 bucks.



I haven't used/have experience with either of the above. Just posting for reference.

Then there is the resistor thing.....


.....seems cheap and easy, it tricks the theft deterrent module into thinking the key/column wiring is fine. Problem is, the theft deterrent module (under the dash) is still being used and can still fail, so it's not really removing the passlock (like a tune would).



Maybe look at it (passlock) this way.

Normal funcion:

The PASSLOCK sensor > The EVO/PASSLOCK module > The VCM/PCM

Resistor bypass:

Resistor > The EVO/PASSLOCK module > The VCM/PCM

Tune:

The VCM/PCM



The tune is probably the best route to take since it eliminates the sensor and module, but if your on a budget and have a resistor / patients / time on your hands and don't mind tinkering (it's inexpensive).

Just getting the correct lock cylinder installed or the resistor trick still requires the evo/passlock module to function correctly (probably does / but who knows until you try).

Best of luck.
 
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