Passlock System

[ponchonutty]

Tell me first what it's doing now when it won't start. What is the security light doing? You may want to try the relearn technique before going any further.

I think we could try to use 2 relays with the proper resistance to fool the system. Again, I don't know for sure it this will work. That's why I want to rule out everything else. You've changed a few things so maybe a relearn would take care of everything????

[xuberantz]

Originally Posted by ponchonutty

Tell me first what it's doing now when it won't start. What is the security light doing? You may want to try the relearn technique before going any further.

I think we could try to use 2 relays with the proper resistance to fool the system. Again, I don't know for sure it this will work. That's why I want to rule out everything else. You've changed a few things so maybe a relearn would take care of everything????

It did the blinking relearn when I put the instrument cluster in, after 10 minutes it stayed on. I turned it off 10 seconds and back on and tried to start, but no go. The light is on again, no blinking just steady..

[ponchonutty]

Well, to do the relearn the light should blink after you crank it. Then shut it off and imediately crank it over. If it doesn't start leave the ignition on for 11 minutes. After then try to start it, if the same happens, leave the ignition on for another 11 minutes and try it again. It's not uncommon to take 45 minutes or longer to do this.

[xuberantz]

Originally Posted by ponchonutty

Well, to do the relearn the light should blink after you crank it. Then shut it off and imediately crank it over. If it doesn't start leave the ignition on for 11 minutes. After then try to start it, if the same happens, leave the ignition on for another 11 minutes and try it again. It's not uncommon to take 45 minutes or longer to do this.

I've done this over, and over and over again, and after the first learn (light blinking) it just stays on after that everytime I turn the key on (even when leaving it for 15 minutes, turning it off, doing it again, and so on so forth).

[ponchonutty]

Hmm, well either somehthings up with the wiring to or from the cluster, the bcm, or the bcm itself is toast. You could try to do a bypass on this system but I've never tried it. I have an idea how to do it but I've never tested it.

[xuberantz]

Originally Posted by ponchonutty

Hmm, well either somehthings up with the wiring to or from the cluster, the bcm, or the bcm itself is toast. You could try to do a bypass on this system but I've never tried it. I have an idea how to do it but I've never tested it.

I understand you've never tried it but at this point i'm willing to try anything, so shoot it at me.

[mvickip]

I am not sure if it is my Passlok system or what. I have 2004 Malibu Classic. Car always starts after it has set for an extended time. It has recently gotten to where if I have been driving it and get out to go into the store for a short time, when I come back it will turn over but not start. Theft light is off. If I try to start two or three times it will typically start. I have been driving and noticed that speedometer and tach dropped to zero for about 2 seconds and theft light flashed and then everything went back to normal and engine continued to keep running. Two days ago when I went in the store and came out the vehicle would not start. Left the ignition on to try the 11 minute trick. After about two minutes doors locked again, buzzer went off, theft light came on and went off. Tried vehicle and it started right up. Similar issues to what is posted but also different. Is this an ignition switch? Would appreciate your thoughts

[ponchonutty]

Sounds like your BCM is going bad or there's a short in the harness for sure. You'll have to take it to a technician and have them hook it up to their scanner. I'm sure it'll say there's a loss of data communication.

Originally Posted by mvickip

I am not sure if it is my Passlok system or what. I have 2004 Malibu Classic. Car always starts after it has set for an extended time. It has recently gotten to where if I have been driving it and get out to go into the store for a short time, when I come back it will turn over but not start. Theft light is off. If I try to start two or three times it will typically start. I have been driving and noticed that speedometer and tach dropped to zero for about 2 seconds and theft light flashed and then everything went back to normal and engine continued to keep running. Two days ago when I went in the store and came out the vehicle would not start. Left the ignition on to try the 11 minute trick. After about two minutes doors locked again, buzzer went off, theft light came on and went off. Tried vehicle and it started right up. Similar issues to what is posted but also different. Is this an ignition switch? Would appreciate your thoughts

[ponchonutty]

Originally Posted by xuberantz

I understand you've never tried it but at this point i'm willing to try anything, so shoot it at me.

OK. You can try this. I think this would be the easiest thing. Find a 555L or 556L bypass from Directed electronics. Hook it up as it states except for the starter wire and ground when running wire and then do the programming it says to. Then get 2 relays and hook one off of the ignition wire to send out a neg. output and hook that to the ground when running wire. Take the other relay and hook it to the starter relay so it sends out a neg. when you crank the car over.

You could do this as well just using relays and resistors but if you haven't really got into one of these systems before I think it'd be a little too daunting.

[03Alero]

Originally Posted by ponchonutty

If it stays lit even when you are not running the engine it's certainly a BCM or harness to the BCM problem with out a doubt.

Ok, I finally got around to disconnecting the BCM for a few minutes before reconnecting. I still have the security light on (solid) whenever the car is running. To recap:

1) I followed the resistor procedure and the car now runs, but the security light is always on
2) I disconnected the battery overnight. When I reconnected the battery, the security light is still on all the time.
3) I disconnected the BCM. No change

Ever since the initial procedure, I have had no trouble with the car not starting. The problem is completely gone. However, I am worried that some day the computer is going to get reset and the car will no longer start and strand me somewhere.

Any thoughts about what to do next?

Thanks again.

[isetheby]

Hi There Folks
First I probably give you the info on what happened to me.
I own a 2003 3.4l impala. I bought it in June and it had 34 500 km. It now has approx 47,000 km. About a month ago a light came on indicating I needed an oil change. I ignored it and about a week later the check engine light came on. I usually only drive in the city, fairly short runs. About 3 weeks ago I drove out of town approx 200km. Stopped in to get some grub, came out, car wouldn't start. Not a gig. Tried a boost, nothing. With the key in the on position, the security light came on along with the battery light and the pic of a car with an opened ended wrench on the side of it. The door transponder wouldn't work or the trunk opener. The power windows buttons worked, the wipers worked but the radio didn't work and the dome lights didn't work. Waited 1/2 an hour, turned the key, perfect. Drove back to town and stopped at a store, come out turned the key, not a gig. Waited 20 mins and it started. Drove the car around in town for 3 weeks not a hitch. Went out of town again (200km) same thing happened. No start. Waited 1/2 an hour and she started. I thought that it might have something to do with the long run. Now the problem is occurring on a daily basis. Broke down the other day, called the dealership and they suggested it was probably the battery. They also told me that they never came across this problem before. What a crock. Bought a battery for $116.00, put it in, car started, eureka, problem solved right, Wrong! Later that afternoon of about 3 stops and starts on the 4th, no start. Waited 1/2 an hour, car started. The next day I decided to go do my business so I took the extra set of keys and would leave the car running, lock the doors with the remote. I would come out press the unlock door button, best kind. Done this about 5 times worked ok. The 6th time it didn't work. Had to use the key to open the door. My buddy is a mechanic and he put it on the scan tool. Apparently it showed a "u" code which is a communication code. Apparently there are 4 computers in the car. The BCM, ABS computer, Air Bag computer and the anti theft. Apparently all these computers are supposed to be yakking to each other. For some reason the anti theft is not talking to the air bag, which in turn is causing my car not to start. What's up with that? If someone needs the exact code numbers let me know.
GM has a serious issue with their Pass Lock system.

Now I have investigated a lot of weird stuff but this one is all GM (To blame).

To make a very long "root cause investigation" short...

1) They (GM) have used connectors in the ignition Pass Lock system which do not
mate up properly.
2) They (GM) did not use gold plated connector pins for this specific application.
3) They (GM) did not understand compensating software for the Body Computer.

The main issue is that, over time, the Pass Lock connector pins oxidize.

This oxidation changes the critical analog Pass Lock signal to the Body Computer.

So the Security light comes on whenever and the car does not start whenever.

You can buy a Pass Lock "bypass kit" online and disable the system... easy and cheap.

I ended up hand soldering the three wires (Black, White and yellow) directly to the
Pass Lock sensor on the ignition switch. Not so easy but it does not disable the security system...

My Impala is finally fixed and it cost me nothing...

So now everyone knows the truth about your expensive GM problem!

Maybe a Consumer Advocacy group would like to contact me as a "key wittiness" in some litigation?

I have a very advanced background in Electronics, Automotive Engine Management Systems and a Degree in Computer Science. Presently I am working as an Embedded Software Engineer.


Dr Zach



I have to go to the Dealer on Monday and their going to do a scan $95.00 an hour and if the ignition is gone and they have to replace it, it takes another 1/2 an hour to program it and I don't know the cost of the switch. Should I try to bypass the Passlock 2 system by cutting the yellow wire and installing a toggle switch.

Thanks
Bill

[ponchonutty]

No. The toggle switch will not cure your problem. You should do the resistor trick like what I've stated before.

[FISH96]

dear isetheby aka dr zack,

this is a nagging problemlok at the size of the thread. is there any chance you able to post the precedure(photos, schematic, location of said components,etc.?
regards and be well, fish96

[ponchonutty]

Interesting. Normally when you do the resistor trick it'll normally either start everytime or won't at all. When you turn the ignition on but not in the run position does the security light flash???? You may need to try the PK2 relearn procedure.

Originally Posted by 03Alero

Ok, I finally got around to disconnecting the BCM for a few minutes before reconnecting. I still have the security light on (solid) whenever the car is running. To recap:

1) I followed the resistor procedure and the car now runs, but the security light is always on
2) I disconnected the battery overnight. When I reconnected the battery, the security light is still on all the time.
3) I disconnected the BCM. No change

Ever since the initial procedure, I have had no trouble with the car not starting. The problem is completely gone. However, I am worried that some day the computer is going to get reset and the car will no longer start and strand me somewhere.

Any thoughts about what to do next?

Thanks again.

[BjoyS]

I have a 2002 Alero,In my manual they refer to this system as a disabler, It doesn't only work for anti theft purposes but disables the ignition when service lights are ignored....Does this cutting the yellow wire and adding a toggle switch work for my car ?? I am sooooo tired of this damn thing going off for no reason...I am a health care worker who drives from home to home and having to wait an extra ten minutes between clients cuts into my paycheque.
Anyone with any help or answers would be sooo appreciated.