Yet ANOTHER "security light" thread.... except...

[covertcelery]

Talking about "cluster"-farks... I have updates on my situation.


So I get the new BCM, install it - I get the new switch, install it. I decided NOT to get a new cylinder (epic failure on my part). Installed everything, etc, yada yada. I also found a wire going to the BCM harness that was slightly damaged... fixed that.


Call around to see who can program the BCM the cheapest. Ends up being a Chevy dealer here in town. The only catch is, the car has to be there for them to program it...


GREAT, so I had to pay to get it towed there. I get that done, I tell them whats up. They say, no prob. About 2 hours into it, the guy comes back and tells me, they flashed the BCM fine, but it still won't start, and KP2 light is still on. I said, prob. the cylinder; and at this point the mech. also informed me that the PK2 sensor is actually built into the cylinder NOT the switch (as I had incorrectly assumed).

So after replacing them screwing w/ it for 6 hours and a cylinder later... The car starts, BUT PK2 light is still on.


At this point, they schlep the car back to me saying that "one of my connections is wrong, replace the connectors on some wires, etc... and bring it back so they can clear the codes; because something was giving very high resistance."


At this point I can see whats going on, they just want me to get the heck out of there because it was closing time. I was thinking "BS", but - anywhom. I take the car back, sauder the three connections going into the switch, and STILL picking up high resistance on the PK2 wire ignition siwtch side...


Took me a day, but got to thinking about it, that there is NO way that I was having wiring issues because before I changed out anything, there was no resistance showing when the car was off. So I knew that it had to have been something that was replaced.







Well, whatdya know. I had my meter on the whole time, and the first thing I took out with the meter on was the "newly installed" cylinder... BAM, immediately took the reistance off as soon as I pulled the cylinder out.


I called them up, told them that their mech. was a moron for not checking the "new" part he just installed and told them that I expected them to work on and replace the cylinder for free. The service manager threw a little bit of "resistance" about it (no pun intended) - but I told him that if I get charged as much as a penny, I would charge them the same amt. charged to me for having to troubleshooting the parts the I paid for them to install in the first place.


He quickly changed his tune.


I will find out on Monday (though I dunno for the life of me why it would take more than 15 min. to change out a cylinder and do a manual relearn) - but at this point I don't care...


This SHOULD fix the problem.


BTW - even tho the PK2 light is still on, I am happy to say that replacing the BCM cleared up ALL the problems w/ flickering lights, etc.


To generalize the problems here that I originally had... Bad BCM, and bad ignition cylinder.






To ALL the people out there having this very same problem... DO THE "RESISTANCE BYPASS" first!

2nd - if that fails, get your ignition cylinder replaced (At a dealer, this will cost you apx $200 + labor... If you do it yourself, you can get a new cylinder for apx $100 +-$10-20)

If you're still having problems, change your BCM out. I was able to buy a reman. BCM for $150 (I also got a credit for returning the old BCM, so really I only spent like $80 on the new BCM). If you get it programmed at the dealership they will prob. just charge your labor to flash the new BCM. (And if you learn by my mistake, it is a good idea to change the BCM AFTER the car is already at wherever you're getting the new BCM flashed - as you will not be able to drive the car if you switch out the BCM)


Altogether IF you decide to do this yourself - expect to pay APX. $150 (new BCM) + $100 (BCM reprogram) + $100 (new cylinder) = $350



BE CAREFUL! Do NOT trust that any "new" component is automatically "good" just because its out of the box...

I had to make the dealer mechanic feel like a complete idiot because I sat there and showed him that the very part this "ASE CERTIFIED" mechanic just replaced was bad, and a regular everyday non-ASE certified guy had to troubleshoot HIS work.


If you are wanting the dealership to do all this work (as I had described above), EXPECT to pay anywhere from $800 to over $1000 (and this is IF the guy knows what he's doing). If you figure that they charged me $200 JUST for the cylinder - and $300 for the labor, you know they're gonna bend you over if they have to replace the BCM as well...











That's it, I will let you guys know what happens on Monday when I get the car back - but this SHOULD work.

[covertcelery]

Also, forgot to mention.

IF this entire thing I just went through works out. I will post DETAILED instructions on how to:

1) Change out the BCM, and the best way to get to your BCM (they are HARD to get to, but this little technique I know will get you in and out in like a minute)

2) How to get to and change your cylinder.

[Colt Hero]

It'll be interesting to see how it works out for you, but how will you know if the problem has been solved? Won't it be weeks (or even months) before you'll be sure? With my Impala ('02, bought new, 111k), I hadn't had a "no-start" SECURITY problem in about a YEAR before I took a long trip and had it happen (at least) THREE times in two weeks!!! This HAS to be a clue as to what the problem is ...

[ponchonutty]

Yep. Too bad you didn't try the resistor trick first. Yes the "code" part of the system is inside the lock itself. That's why if a crook rams a lag bolt in it via cordless drill it'll break it making it unable to start. That's also why super long and heavy keychains mess up these system too.

[covertcelery]

Originally Posted by Colt Hero

It'll be interesting to see how it works out for you, but how will you know if the problem has been solved? Won't it be weeks (or even months) before you'll be sure?

Yes, I've already anticipated someone asking me this.

The answer is: It should undoubtedly return when either the BCM, or the cylinder fail (or start to fail) again. As a matter of fact I expect it to return, BUT hopefully not anytime soon.

Now, unless you happen to be one of those unlucky bastages that actually happen to have problems w/ a wire or something - sucky deal, that is the absolute worst case scenario...


BUT, more ofthen than not it is some sort of board or mechanical failure... So you start changing things one by one, it will (should) fix the problems... lol

[covertcelery]

Alright guys, here is the semi-short of it...



Got the car back today, I don't have a lot of time to post the specifics on here, but ends up being that the cylinder WAS bad - BUT (to throw another friggin curveball into it) - my aftermarket remote start/security system was also the culprit... This was taken out, and poof - no more security light.

And btw - you can't just "take out the control board", you actually have to splice the wiring back up...


So in my case; I had almost the worst case scenario (besides a wire going bad somewhere). Almost every component that had anything to do w/ the PK2 system (and how it works based on resistance) completely failed.

In review, here are the list of things I had to do to my vehicle:

-BCM change and flash new BCM
-Ignition switch change.... (although you probably WONT have to do this, I just replaced it because I wanted every component in there that had anything to do w/ the PK2 to be new)
-Ignition cylinder replace.
-Remote starter/aftermarket security system had to be completely bypassed.



Not everyone will prob. have to change out their BCM - but in my case that's what was causing all the lights flickering and general "body function" failures.




If you want your security light to go off, I would do things in the following order:

1) Do the resistance bypass method...
-IF your car already has an aftermarket alarm system or a remote starter, chances are you probably already have a bypass installed.


2) Change out your ignition cylinder. (The passlock sensor is inside this cylinder - sometimes, like in my case, they completely fail)


3) If you already have a remote starter installed AND have a bypass (which those two will prob. go hand in hand) - BYPASS the entire aftermarket security/remote starter system. You can't just unplug it - you will have to re-splice the wiring as well.


4) If that still didn't fix the problem, replace your BCM - this is actually cheaper than you think to do.




If you let a dealer do all this, expect to pay over $1500 easy, but you can do it yourself for not a 1/5th of the cost...











Security light gone ladies and gents, and just to make sure you guys understand... At some point - in theory anywho - the chances are good that those whom not had this problem before on their car, will eventually have this problem. I DO EXPECT mine to possibly come back, but when it does I have a game plan. As a matter of fact, I know the underside of a Chevy better than the back of my hand now....



Good luck.

[HeMi101]

Your a jinx or something Celery. I've been getting my Security light every 3rd time i start my car, and its startin to Bother and worry me. But I'm probably gonna buy used Cylinder with its key for ~25$ from a wrecker when it happens, so it's all good, as long as my remote entry works.

And yes there are some problems like the passkey and that, that WILL return. But It should be a good 60 or 70K Miles before that happens. Long as you don't do alot of disconnecting the battery, or have to jump start it often, I would doubt your BCM problem will come back. Could even be, if your Remote start was a problem, maybe it was installed wrong or very crappily, and that IT Caused that problem. so with it bypassed, Again shouldn't happen.

[ponchonutty]

Covert, you never stated that you had a remote starter installed. A well built and properly installed remote start should never have caused the issues you stated. I've been doing remote starts for over 13 years now and have yet to see a remote start cause this. I have however, seen the install be the root of the cause of problems. Even if a botched install, I'd would like to know what conclusion came about stating that the bypass was the issue.

[covertcelery]

Originally Posted by ponchonutty

Covert, you never stated that you had a remote starter installed. A well built and properly installed remote start should never have caused the issues you stated. I've been doing remote starts for over 13 years now and have yet to see a remote start cause this. I have however, seen the install be the root of the cause of problems. Even if a botched install, I'd would like to know what conclusion came about stating that the bypass was the issue.

Poncho, let me stress that the problem was NOT the wiring with the remote start. The circuit board on the aftermarket alarm system started throwing high resistance. I know this because I myself kept the module after they took it out. After inspecting the circuitry boards, it seemed that it was due to either faulty capacitors and/or resistors on the board itself.

And just so its clear, the "bypass" was not the issue at all. The bypass module was installed and working correctly, but the bypass module and the aftermarket alarm were actually two different modules (circuit boards). So essentially they could have just left the bypass on there, but they decided to remove it as well just to ensure that there was nothing aftermarket on it... And I didn't have a problem at all with that, because if I ever need to do the bypass again on it, I could easily splice one back in. Just FYI: It was an model "ASPASSIII" (the bypass module).


We need to ask the mods to make this a sticky thread, because this happens ALL too often, and there does not seem to be a "definitive" guide. And trust me, from what I've gone through - I decided to dwell DEEP into this issue and make sure and get this resolved.

As a matter of fact, one of the guys that I attend church with has same type of vehicle, and guess what: PK2 light issues as well. I told him he was in luck, because I know what to do. In his case, he only had to replace ign. cylinder and BCM. He got all that done for apx. $200 - and no PK2 light (btw - he was starting to have random light flickering issues as well, and that's what tipped me off to possible BCM problem).

But just a quick report, since the whole incident being finally "resolved" apx. 2 weeks ago. The Impala has had no PK2 lights, and everything works like an absolute charm - like its supposed to... Yes, ladies and gentlemen - Chevy's can start and run, but sometimes its at a cost to you.

[covertcelery]

I also wanted to personally thank you Poncho and Hemi for all the good insights into this problem.

I hope that the admins could possibly STICKY THIS THREAD so that other users that have this very same problem have some sort of refference to be able to jump to without having to look through TONS of threads to piece together the answers.

I mean I litteraly had to research this problem for at least 2-3 weeks and try to put the puzzles together to finally figure out where I needed to check and to start, and what I needed to do and look out for. I mean I had to go through at least one huge thread about this PK2 light that was apx. 20 pages long and try to puzzle together all the pieces from those 20 pages.

PLEASE MODS, MAKE THIS A STICKY SO THAT OTHER PEOPLE DONT GO INSANE! THE THINGS MENTIONED IN THIS THREAD ARE ALL VIABLE FIXES FOR THIS PASSLOCK 2 ISSUE THAT A LOT OF PEOPLE ARE EXPERIENCING AND KEEP STARTING NEW THREADS ABOUT.

[ponchonutty]

No problem. I'm just glad you got it back on the road.

[HeMi101]

Just wanna throw one thing in if it was to get stickied (I don't know if its been said in this thread anywhere), don't suddenly think your ignition switch needs replacing. Try cleaning your ignition and try your spare key for a week or 2, as a worn key causes the message too.

I've had problems with getting key cut right, so i got sick of this one sided key (only works if a certain side of the key is pointed up.) so i switched to another key, and no PL2 message for bout a week now.

a good sign that your ignition might be going is: At night, the courtesy lights don't come on when you pull your key out or if you jiggle your key with your door open, and it stops dinging.

[Colt Hero]

Over a year went by with no SECURITY light or starting problems, then a long road trip and three failures in two weeks, and now over two months removed from the long trip and no failures or lights again.

No remote starter or any other aftermarket stuff on my car. No cluster problems or other weird stuff going on with my car. Car was also purchase brand new and has never been touched in 112k miles now by anyone other than me and the workers at the Chevy plant.

CovertCelery :

Your car may be "fixed", but how do you know which part was the problem if you changed everything out at the same time?

I wish I had the tools to debug this problem myself. Probably could figure it out very definitively in less than one day.

[HeMi101]

Colt, Could of been a dirty key (dropped it or got something on it) and caused problems. Then dirt rubbed off the key and presto no problems right now.

& I Will Gareentee replacing the Ignition Cylinder is what fixed his PKII messages, and the BCM fixed the stupid light problems he was having.

[Colt Hero]

I don't think it was a dirty key. The failures that occurred during that long road trip occurred with two different keys. If I end up doing ANYTHING at all to correct this problem, it'll probably be a new ignition switch. Then, I'll have to wait another year or more to be reasonably sure the problem is gone because it happens so infrequently with my car.

I just wish I could look at the stupid program loaded in the computer and debug the problem backward to the source...