Passlock II SECURITY light and truck won't start!

[tlamot01]

OK, since the last time anyone seems to have had this problem was about six months ago, I thought it might be time to start a new thread.

I definitely have this SECURITY / Passlock II issue as well on my 98 Yukon. My situation may be a bit more unique than others though. Hoping some of you can chime in on whether I even need to replace my key sensor since it is already bypassed with a Directed Electronics module (part of my remote start installation).

This morning, I got the dreaded blinking SECURITY light and fuel cutoff indicating a bad Passkey II value sent to the computer. Despite all efforts, I could not get the truck started and had to hitch a ride to work.
About two months ago, I had tore down my remote starter and bypass module wiring. I confirmed that the ignition yellow wire had the same resistance value as my bypass module. I then proceeded with SOLDERING all connections, thinking my problem may have been related to faulty wiring.
The truck ran fine since then and I really believed I had resolved this. However, recently I'm being haunted by this.

So, my questions here are:

Is there any way to confirm without a doubt the resistance value the computer is programmed with outside of testing what the ignition switch has? Maybe I'm off a few ohms...

How does the ignition switch come into play when a bypass module is installed. Isn't that the point of having one - so you don't have to rely on the ignition switch anymore?

If my bypass module is 'dialed-in', why am I still getting a SECURITY light!?

 

[992dr]

I feel your pain. I went through the same thing. I even had a remote starter installed to, all connections were soldered as well. It is in the ignition lock housing. It is considered a wearable part, too much wieght on your keychain is the biggest reason for this to happen. You cant just replace your lock cylinder like the older trucks/cars. When I did mine, I replaced both parts because I did not want to take any chances. This was an ongoing problem that left me stranded as well as my family. This started in July of 09 when moving down to NC. It did it very infrequently until 07/10, then It started to happen almost every week and it came to a point where it happened on a daily basis. Waiting times ran from ten minutes to over an hour for it to start. Sucked to say the least.

This is my thread with part numbers for the parts needed.
http://www.gmfullsize.com/forum/showthread.php?t=199600

Good luck, if you need any info, dont hesitate to ask.

 

[tlamot01]

Thank you. This morning has been all about reading your link. My truck is sitting on a charger right now because after extensive attempts to get the truck to re-learn the Passlock code, my optima battery had just about died.
I did read in other forums that I could disassemble and clean the six contacts off (some said theirs were burned?)
Any chance you know where I can get a picture of these parts and maybe how exactly to remove them? I just want to know what I'm in for if I drop another $300+ into this money pit.

http://www.gmfullsize.com/forum/showpost.php?p=4120063&postcount=42

 

[tlamot01]

Just found this site. Perhaps a way to bypass the Passlock without purchasing an aftermarket kit/alarm add-on. Seems like it would apply to all vehicles, but perhaps those of you out there with more experience than I can confirm this.

http://www.bergerweb.net/PasslockFix/index.shtml

 

[992dr]

Thank you. This morning has been all about reading your link. My truck is sitting on a charger right now because after extensive attempts to get the truck to re-learn the Passlock code, my optima battery had just about died.
I did read in other forums that I could disassemble and clean the six contacts off (some said theirs were burned?)
Any chance you know where I can get a picture of these parts and maybe how exactly to remove them? I just want to know what I'm in for if I drop another $300+ into this money pit.

That sucks about your battery, it should only take 30 minutes to do the re-learn.
I'm sorry, I'm not having any luck finding those images. Get in touch with GMPartsdirect.com, not only do they have the best prices they should also be able to get you images of each item or maybe a schematic.
To be brutally honest, its a PITA to do. You have to remove your steering wheel, airbag, the steering wheel column cover, hmm I'm sure I'm missing something. You'll also need a special tool to remove the ignition lock housing, I made one, if you need it let me know. The ignition harness was a lot easier but, you still have to reach into pretty tight places and get in uncomfortable positions.
It took just about a day from start to finish.

Just found this site. Perhaps a way to bypass the Passlock without purchasing an aftermarket kit/alarm add-on. Seems like it would apply to all vehicles, but perhaps those of you out there with more experience than I can confirm this.

http://www.bergerweb.net/PasslockFix/index.shtml

I am not too fond of modifying electronics, regardless of the situation. I'm sure others are but, me, I'll stick with the books and do it right.

If you need anything dont hesitate to ask

 

[tlamot01]

OK, after three attempts to 're-learn' the Passlock password, the truck started. Now my security light stays lit (for how long I don't know). This morning, the truck fired right up even with the lit security light.
How long I can go without having to do this again is anybody's guess.
The only positive thing about this is that the entire fix cost me $0, and very little pulled hair.
As long as this re-learn procedure continues to work, I won't thing about modifying the wiring beyond the existing Passlock bypass module that's already installed.

PS. I'm waiting on a response from GMPartsdirect about those two items. I will post what I get.

 

[992dr]

The re-learn is for after you install the new parts. Then you do the re-learn once and you wont have to do it again. If you do the re-learn before replacing the parts, you will be doing it quite often.
The first time my truck stalled was in July of 09 and finally broke down and fixed it one year later. To give you an idea, it would stall on start once a month maybe for a few months. Then it would stall once a week, then twice a week, then every day until it started happeneing several times a day. The suck part is, you never now when its going to happen.
I guess my point is, do it once and do it right. I would hate to see someone else go through what I went through. I no longer have any hair

Modifying the harness is a little sketchy to me. It is there for a reason, thats how I think of it. Now that its fixed its not a worry/problem.

Did you search those part #s on GMParts? Not bad prices. I believe it was under $250 for both.

 

[tlamot01]

So again, I'm going back to the bypass device that is already installed. Isn't this supposed to do exactly what the new ignition sensor already does - mimic the resistance value that the hall-effect generates when you turn the key? So if the bypass is in place and working (required cutting the yellow wire, so I don't even see how the key comes into play at all), then why am I even getting a Security fault condition at all?
Maybe there's something about this system that I'm missing...
Without bypass: Key turn creates resistance value read by hall-effect; sends resistance value to BCM; BCM confirms value; sends 'password' to ECM; allows fuel injectors to operate.
With bypass: Bypass module sends resistance value to BCM when +12 is sensed on IGN2 (usually initiated by remote start sequence or key is turned in cylinder); BCM confirms value; sends 'password' to ECM; allows fuel injectors to operate.
^^
Right? If this is true, then maybe my BCM is forgetting the resistance value? I just don't see how changing out the hall-effect sensor in the ignition switch is any different than just mimicking the existing value through a bypass module, especially since the yellow wire has been cut.

(My bypass module is non-programmable and requires the cut wire unlike recent units that I've researched that simply tap into all three of the Passlock wires - although should still achieve the same result...)

---------- Post added at 01:42 PM ---------- Previous post was at 01:37 PM ----------

PS. I still have my ignition switch fully exposed. I'll take some pictures and post them here. Maybe since you've already done this, you could point out what exactly needs to be replaced or cleaned.

 

[992dr]

It was a while ago, I dont remember everything. I try to forget as much as I can about that whole situation, hah.

The easiest way to explain this is. Its a wearable part. The part that the key goes in has a magnet, it wears over time, and the security system does not recognize the key, hence the security lite. Thats when I was saying more wieght on your key ring causes this problem. Like the older trucks, you used to be able to remove the cylinder and be done. Now, you have to replace the whole housing because GM decided to add the security device to the ignition system. I replaced my ignition harness as well to be on the safe side. I wanted everything to be back to factory spec.

What year is your truck?

 

[tlamot01]

OK, I did get a response from GMPartsdirect

Dear Mr. Lamothe,

Part number 26049449 is for the ignition cylinder case, which includes the passlock sensor.

Thank you,
Adam Wilkins.


-----------------------
Re:
According to many forums, I need a new Passlock sensor. I\\\''ve been given the part number: 26049449. You list it here, but there is no diagram or picture. Can I get this info to confirm I\\\''m buying the part I actually need?

Symptom: Security light blinking and engine refuses to start even after the long-tamper cycle of 10 minutes has completed.

-TiM

So it appears that they either don't have a diagram or just didn't bother to send me one. I took some pictures of my exposed steering column. Perhaps you can point out what changing part 26049449 actually involves.

 

[ScottyBoy]

If you already have a bypass for your remote start, does your remote start ever give you problems starting like it does with the key?
Also, the bypass module does not permantly bypass the passlock system. There is a trigger wire on it that is energized by the remote start module. So only when the remote start is activated is the bypass active and working. If you wanted to have your bypass modue permanantly bypass the passlock, you could just ground that trigger wire.

Just found this site. Perhaps a way to bypass the Passlock without purchasing an aftermarket kit/alarm add-on. Seems like it would apply to all vehicles, but perhaps those of you out there with more experience than I can confirm this.

http://www.bergerweb.net/PasslockFix/index.shtml

Also, the way its permanantly bypassed in that link is actually a very reliable way of bypassing it. I used to be an alarm/remote start installer and back before the bypass modules even hit the market thats how we used to bypass the passlock when installing a remote start. The only difference was that we wired it to a relay so that it was only active when triggered by the remote start. The ONLY time I have heard of any problems with the resistor bypass is in severely cold climates up north where temps dip below 0 degreez for extended periods.

 

[tlamot01]

Scott, when the truck displays symptoms of Passlock failure, the remote starter will not work either. So you're telling me that the bypass module is passive and only activates when it is triggered by the remote starter; perhaps through a relay triggering the bypass's resistance value through the yellow wire and back into the ignition switch?

Then this leads me to believe there is still some common wiring or connectors between the two units that may be faulty. I recall cutting the yellow wire and attaching both ends of it to leads from the bypass module. I don't think the other two wires were cut, but maybe one of them (middle orange/black wire) was tapped into...

Perhaps the BCM is the issue then, since both systems now feed into it?

PS. Day three and the SECURITY light is still on, but truck continues to start...

 

[ScottyBoy]

Scott, when the truck displays symptoms of Passlock failure, the remote starter will not work either. So you're telling me that the bypass module is passive and only activates when it is triggered by the remote starter; perhaps through a relay triggering the bypass's resistance value through the yellow wire and back into the ignition switch?

Then this leads me to believe there is still some common wiring or connectors between the two units that may be faulty. I recall cutting the yellow wire and attaching both ends of it to leads from the bypass module. I don't think the other two wires were cut, but maybe one of them (middle orange/black wire) was tapped into...

Perhaps the BCM is the issue then, since both systems now feed into it?

PS. Day three and the SECURITY light is still on, but truck continues to start...

You are describing a DEI 555L module. Thats EXACTLY how it wires in. You cut the yellow wire and each end connects to the 555L module. See if you can find the module and confirm that it is indeed a 555L. If so, you should be able to ground the blue/black wire and have it be permanantly bypassed. The blue/black wire should be connected to a wire on your remote starter. Try cutting it off of the remote starter and permanantly attaching it to ground. But make sure its not in anti theft mode when you do that or it will not work.
Also, that may put a drain on your battery . If it does, you may want to wire it up to a switch.

 

[ScottyBoy]

You get this figured out yet?

 

[992dr]

You get this figured out yet?

I'm also curious to know.

 

[tlamot01]

Honestly guys, I had to get the truck in for smog/safety inspection so I could get it registered here in Missouri. Once the thing started working again (after the 30 minute passlock relearn procedure), I put the dash and column back together. So far, the truck continues to start but the security light is still illuminated. I read somewhere that the fault code remains for 100 ignition cycles. I'm not about to start my truck 100 times just to test that...
Now that I'm registered, I might re-visit this problem this weekend (with pics). Thanks fellas.

 

[992dr]

It sounds about right. At first it would happen every other month.
Good luck, check back in and let us know.

 

[letsbangout]

This all sounds like foolishness to me. I, too, have persistent Passlock problems. I'm prepared to permanently disable Passlock by buying HPTuners' software and programming the PCM not to act on the injector enable signal (yes, you can do that. Why more people on this board don't talk about it, I don't know.) Or I might be able to disable it by generating the TDM's "enable signal" and feeding it straight to the PCM. That seems to be my problem (like countless others) - that the TDM/BCM are inherently broken by design, and it doesn't matter what resistance you feed it, it's still broken. My research has revealed two candidates to fix this on a permanent basis:

DIY: http://home.hiwaay.net/~davida1/passkey.htm

Commercial: http://www.bakerelectronix.com/products_vats/

The only thing puzzling to me at this point is which signal line do I use? I can't identify it on the PCM, per this diagram: http://www.tahoeyukonforum.com/forum/showthread.php?t=28479 and on the BCM wiring diagram as well.

Does anyone have experience with these or similar bypass mechanisms that also bypass the TDM/BCM? And which signal line to feed the PCM with on a 99 Yukon?

 

[letsbangout]

This all sounds like foolishness to me. I, too, have persistent Passlock problems. I'm prepared to permanently disable Passlock by buying HPTuners' software and programming the PCM not to act on the injector enable signal (yes, you can do that. Why more people on this board don't talk about it, I don't know.) Or I might be able to disable it by generating the BCM's "enable signal" and feeding it straight to the PCM. That seems to be my problem (like countless others) - that the TDM/BCM are inherently broken by design, and it doesn't matter what resistance you feed it, it's still broken. My research has revealed two candidates to fix this on a permanent basis:

DIY: http://home.hiwaay.net/~davida1/passkey.htm

Commercial: http://www.bakerelectronix.com/products_vats/

The only thing puzzling to me at this point is which signal line do I use? I can't identify it on the PCM, per this diagram: http://www.tahoeyukonforum.com/forum/showthread.php?t=28479 and on the BCM wiring diagram as well.

Does anyone have experience with these or similar bypass mechanisms that also bypass the TDM/BCM? And which signal line to feed the PCM with on a 99 Yukon?

So in the absence of any relevant replies, I decided to buy the e-book from http://newrockies.com/the-problem-and-the-solution/diy/ to build a VATS/Passkey bypass mechanism. This is the same circuit I referenced above. The reason I bought it is because 1) I figured it would include instructions on how to interface it to the PCM (which it does), and 2) I didn't realize that module is only for VATS/Passkey systems, in other words, cars with stand-alone Theft Deterrent Modules, of which 97+ Tahoes/Yukons are not (because the TDM is integrated into the steering control module). It was probably not money wasted, because I'm now of the opinion that the only real way to deal with this, besides buying one of NewRockies' "Pro" modules (I'm guessing it's something that taps onto the serial interface of the TDM and tells the PCM it's ok to start the truck), is to break down and get a tune with HPTuners of EFIlive software that instructs the PCM not to look at the TDM's status.

Before I do that, though, I'm going to pull out my Steering Control Module (because my power steering is acting up - it seems to be commanding max pressure from the pump at all times, even with the steering position sensor disconnected - not sure if that's normal behavior). Since I already have the yellow Passlock sensor wire clipped, I may solder in a resistor directly to the SCM. So unless the SCM is broken (which it could be, given what I said above), it should work for a while. But I swear I'm going to start socking away money to buy HPTuners Pro package for $650 and turn this big negative into a positive.

 

[slipping]

Awesome research. I'm gonna try and get the items necessary to build me one of these deals. For both the Tahoe and my camaro. Right now I have a wire running from the relay under the Hood to a spot next to ground so when I turn key and touch it starts. Ghettofabulous

___________________________
99 4 door Hoe lifted
04 Hoe stock
94 z28 lowered, being referbished