Passlock System

[ponchonutty]

Originally Posted by anthony458

I installed the toggle switch two days also. everything seems to be working fine. Am I to understand, that if my battery dies, i will not be able to restart the car regardless of the condition or postion of the toogle switch.

You are correct. At that point it's dealer time and they love to charge an extra $300 to deal with your modification. The resistor trick will work 99% of time. The toggle switch works as well but like you stated, once the car's battery fails or the BCM gets reset, the car will not start. Plus, you'll have to see the PK2 light on all the time while you are driving.

[John Oliver]

I recently tried the Resistors on My Girlfriends 2000 Grand am, I checked the Resistance and came up with 1292 ohms, I purchased 2 Resistors 1-1000ohm and 1-330 ohm for a Total of 1330. I Soldered the resistors to the Yellow Wire going into the Dash and the other end to the Black Wire. I started the Car and the Security light was still on, I checked the Connections several times and everything checked out. Why was the Security Light still on?? I ended up putting it back the way it was until I found out an Answer to Why the Security light did not go out. Any ideas??

[ponchonutty]

check your pm

[Pipeou812]

Greetings,

Same Passlock problems as everyone else... blah, blah, blah... sad but that's GM. Here are few hints from the resolution on my 98,000 mile 2001 Olds Alero. I didn't have to take the radio or heater controls out... all I had to do was take out the two 7MM bolts that hold in the frame/bezel around the instrument cluster (Speedometer, Tack, Etc). They're located on the top of the bezel. Once the bolts are out put the Tilt wheel in the lowest setting and pull the frame straight towards you. Now unplug the Trip Reset button and you have all the room in the world to work on that magical yellow wire because it's sitting right there in front of you with enough slack to add wiring for a switch.

While I had the instrument cluster bezel out I ran the toggle switch wires over to the fuse box by the drivers door and installed the switch there. In a Grand Am we had the switch was right under the dash and occasionally got hit accidentally... nothing but trouble. With the switch now in the fuse box there's no way to accidentally hit it.

Using this method will take you minutes to complete and with no risk of damage to the radio, radio bezel or console plus you'll be comfortable working on it in the driver's seat rather than like a contortionist in the radio opening.

[Pipeou812]

Greetings,

Same Passlock problems as everyone else... blah, blah, blah... sad but that's GM. Here are few hints from the resolution on my 2001 Olds Alero. I didn't have to take the radio or heater controls out... all I had to do was take out the two 7MM bolts that hold in the frame/bezel around the instrument (Speedometer, Tack, Etc). Once the bolts are out put the Tilt wheel in the lowest setting and pull the frame straight towards you. Now unplug the Trip Reset button and you have all the room in the world to work on the magical yellow wire because it's sitting right there in front of you with enough slack.

While I had the instrument cluster bezel out I ran the toggle switch wires over to the fuse box by the drivers door and installed the switch there. In a Grand Am we had the switch was right under the dash and occasionally got hit accidentally... nothing but trouble. With the switch in the fuse box there's no way to accidentally hit it.

Using this method will take you minutes to complete and with no risk of damage to the radio, radio bezel or console plus you'll be comfortable in the driver's seat rather than like a contortionist in the radio opening.

[Pipeou812]

Greetings,

Same Passlock problems as everyone else... blah, blah, blah... sad but that's GM. Here are few hints from the resolution on my 98,000 mile 2001 Olds Alero. I didn't have to take the radio or heater controls out... all I had to do was take out the two 7MM bolts that hold in the frame/bezel around the instrument cluster (Speedometer, Tack, Etc). Once the bolts are out put the Tilt wheel in the lowest setting and pull the frame straight towards you - the two clips on the bottom will release. Now unplug the Trip Reset button and set the bezel aside... you have all the room in the world to work on that magical yellow wire because it's sitting right there in front of you with enough slack to cut and add the toggle switch wires.
While I had the instrument cluster bezel out I ran the toggle switch wires through the openning and over to the fuse box by the drivers door and installed the switch there. In a Grand Am we owned, the switch was right under the dash and occasionally got hit accidentally... nothing but trouble. With the switch in the fuse box there's no way to accidentally hit it.
Using this method will take you just a few minutes to complete and with no risk of damage to the radio, radio bezel or console plus you'll be seated comfortable in the driver's seat rather than like a contortionist in the radio opening.
By the way... the car does NOT have to be running to do this... just remember to swtich the switch to the "on" or "closed" mode when starting the car the first time. Once it's running, throw the switch to the "off" or "open" mode and the "security" light will come on. Repeat the process if you ever have to change the car's battery.

[Pipeou812]

Greetings,
Same Passlock problems as everyone else... blah, blah, blah... sad but that's GM. Here are few hints from the resolution on my 98,000 mile 2001 Olds Alero. I didn't have to take the radio or heater controls out... all I had to do was take out the two 7MM bolts that hold in the frame/bezel around the instrument cluster (Speedometer, Tack, Etc). Once the bolts are out put the Tilt wheel in the lowest setting and pull the frame straight towards you - the two clips on the bottom will release. Now unplug the Trip Reset button and set the bezel aside... you have all the room in the world to work on that magical yellow wire because it's sitting right there in front of you with enough slack to cut and add the toggle switch wires.
While I had the instrument cluster bezel out I ran the toggle switch wires through the openning and over to the fuse box by the drivers door and installed the switch there. In a Grand Am we owned, the switch was right under the dash and occasionally got hit accidentally... nothing but trouble. With the switch in the fuse box there's no way to accidentally hit it.
Using this method will take you just a few minutes to complete and with no risk of damage to the radio, radio bezel or console plus you'll be seated comfortable in the driver's seat rather than like a contortionist in the radio opening.
By the way... the car does NOT have to be running to do this... just remember to swtich the switch to the "on" or "closed" mode when starting the car the first time. Once it's running, throw the switch to the "off" or "open" mode and the "security" light will come on. Repeat the process if you ever have to change the car's battery.

[AD2BU]

Well, here are a few of my thoughts on the Passlock system after reading the factory manual. First, I don't see the point of tying the yellow wire to ground using resistors. The system does not measure resistance, it works on voltage. Each ignition lock has a different code voltage based on the resistors in the lock. This changes the voltage sent along the yellow sense wire. Tying that wire to the black wire with resistors seems to be taken from some websites that deal with shutting off the Passlock system when installing an aftermarket starter or alarm. However, the key piece of information left out is that after measuring the resistance, the resistance is then programmed into an electronics box that is wired into the vehicle. Since this box gets 5V power from somewhere else in the vehicle, it doesn't tap into the reference voltage wire going to the switch. So, you'll probably get the same result of you just wire the yellow wire to the back wire. Or, you could use any resistor since you are going to "relearn" the system anyway.

In my opinion, you could achieve a voltage drop to fool the system by placing one or two diodes in series from the hot wire (or any 5 V wire) to the black wire. Typical diodes drop 0.7 V so this gives a 1.4 V drop - enough to fool the BCM after it is relearned. Make sure the diodes are placed in the right orientation. And note, you are not using this as a diode, just as a voltage dropping device. This is probably easiest to do by the BCM (located under the dash on the passenger side of the vehicle). Just my thoughts.

Finally, the relearn sequence (according to the factory service manual) is:
1. Turn the key all the way to start and then let it come back and stop at the run position. This assumes the car won't start.
2. Leave the key in this position until the Theft light stops flashing (about 10 mins.).
3. After the light stops flashing, turn key off for a few seconds and then you can start the vehicle.
I have found that sometimes the Theft light comes on after doing this procedure while driving and then goes out after a few minutes.

One final note, I checked the BCM on my 98 Malibu and found corrosion on some of the pins that corresponded to the Passlock system. I cleaned them off and recrimped these for a better connection and have not had a problem yet, but it has only been a couple of weeks.

Good luck everyone. Hope my ramblings are helpful to someone. I just thought some of the misinformation in the string might steer someone to the wrong solution.

[ponchonutty]

You've got it sort of right. That yellow wire actually does have a small amount of voltage and when you put a resistor to ground on that wire causes the BCM to read that. I've tried just tying the one cut end of the yellow wire to the black reference wire then do a relearn but it wouldn't work. On vehicles that don't run at all I have found that a resistance between 3k to 5k ohms work best. Sometimes I don't use the black or orange/black (if doing a truck) because for some reason that's the problem. Instead I just take the other end of the resitor to chassis ground.

[AD2BU]

Y'know, after reading your post that sounds right. The system should give an error and not work if you give 0 V on the sense wire. It still seems that the resistor just ties the sense wire to ground, but there may be a small amount of residual voltage in the system. Thanks for the info.

[ponchonutty]

Well, I haven't actually went all the way through it. I just happened to find a way around these PK2 errors. Technically from very high up on the design food chain at GM, doing the resistor trick shouldn't work. There is suppose to be a time sequence from when you first start to turn the key until when the correct code is sent. That's why on a working system, the correct code isn't transmitted until you crank it to start. The system is suppose to read that initial code then read it again when cranking it but, I've found these systems ignore the initial reading. That's why you can permenatly bypass it with resistors.

Furthermore, I'm sure there are vehicles out there that would be fine relearning the code at 0 ohms. It's just that I've tried it before but it didn't work. I'm usually under a time line so I can't always screw around it so I use what I know works.

[bevil77]

Well I own a 1999 Alero and had the same Passlock problem for about a year now. I finally came across this wonderful forum and saw the post about cutting/disabling the system. So I did that, cut the wire behind the column and everything. Printed out the pictures and made sure I did it right. So after that it worked fine till recently. Its still not starting sometimes and left my wife stranded 2 times since I've been deployed. What else am I supposed to do? Any suggestions?

[ponchonutty]

What exactly did you do? Did you install resistors? If so, you may need to recheck those to make they didn't fall apart. Also, if you didn't get the value dead on, you may need to fix that. The resistors actually will change their value a bit with heat and humity. If all the above is fine then try the passlock relearn sequence.

[lipstickhippie]

I just took these directions to my mechanic and it took them five minutes to disable the Passlock and they didn't even charge me. Thank You! Thank You! Thank You! I am sooooooo grateful for this.

[lipstickhippie]

Anyway I had gotten these directions from an earlier post and like I said, it took my mechanic five minutes to do it and no more Passlock! Thanks to whoever posted these earlier!


Yeah, I'm not so sure that the toggle switch is original equipment. As for disabling Passlock 1 or 2, it can be done fairly easily. I did this to my 2002 Olds Alero with Passlock 2. Yours is apparently Passlock 2 also according to these photos that follow. You don't have to install a toggle switch, but I would suggest it in case you go to a dealership for service and they need the Passlock re-enabled. I'm sure they will try to tell you that you shouldn't do this. You can just print out this article to educate them on their own system. The BCM is already programmed to go into "fail-enable" mode when the key reference circuit (yellow passlock wire) is broken (cut) while the engine is running. That's the key ---- while the engine is running. The security/anti-theft light will come on and stay on until the circuit is repaired. Your Passlock is now disabled. Just don't repair the circuit (reconnect the wire) unless absolutely necessary. I have read where others just tape up both ends of the cut yellow wire and leave it that way. This probably works fine, but I like the idea of being able to repair the circuit by the flip of a switch. (Just in case.)

This is the MOTOR AGE article describing "fail-enable" mode:
http://www.motorage.com/motorage/dat...09/article.pdf
page 3, If the correct key is in the cylinder and that circuit
fails while the engine is running, this is considered a
malfunction, not a theft attempt. The “Security” light
may turn on to warn of a system malfunction, but even if
it doesn’t, a key recognition circuit failure with the proper
key in the lock will cause the TDM to enter what GM
calls a “fail-enable” mode. Essentially, the theft-deterrent
system goes offline and the engine will start and run
with any key that turns the lock.

Here are 2001 Malibu photos to help you get to the Yellow Passlock 2 wire to cut it while the engine is running. Read the directions below each photo. By the looks of these photos, you should probably go ahead and start your car with your key (no keyring or keys attached) so you won't have to figure out how to start it with the Switch in an unsecure position later in the process.

http://www.directwholesale.net/diagr...1&link=BULLDOG

http://www.directwholesale.net/diagr...2&link=BULLDOG

http://www.directwholesale.net/diagr...5&link=BULLDOG

http://www.directwholesale.net/diagr...6&link=BULLDOG

http://www.directwholesale.net/diagr...8&link=BULLDOG

http://www.directwholesale.net/diagr...9&link=BULLDOG

http://www.directwholesale.net/diagr...2&link=BULLDOG

http://www.directwholesale.net/diagr...5&link=BULLDOG

http://www.directwholesale.net/diagr...7&link=BULLDOG

That yellow wire is the one to clip while the car is running! Incidentally, Malibus, Grand AMs and Aleros are all having the same Passlock problems. Coincidentally, we all have the same part # for the Ignition Lock Cylinder. A Passlock sensor is built into this cylinder. If this sensor goes bad, you have to replace the entire Ignition Lock Cylinder. GM is making a killing and so are the dealerships. I'm not knocking the Certified Technicians, they are just doing what they are trained to do. How can anyone deny that this part is defective? If you are tired of having to wait to start the car that you worked so hard to buy with your own money, you should be able to disable the Passlock if you want to. This is just one way to do it. Here is the Ignition Lock Cylinder part # and I hope this disablement will really help some of you.
1999 - 2004 Alero
1997 - 2003 Malibu
1999 - 2004 Grand Am

The GM part number is 12458191.

Can't find the old post now but I am so grateful to whoever submitted it. Fantastic!