ARGGHHH! Passlock prob?

Probably 3 times in the last 6 months my wife's Alero wouldn't start for work in the a.m. Each time the car started when she got home after getting a ride to work. Today it again would not start in the morning and hasn't started all day. It really sounds like the dreaded passlock issue since it is cranking and the security light is on (not flashing and the engine light is on too). However, I have tried the procedure numerous times that should reset the security portion of the system( 10 minutes in on position, 10 secs off etc.) with no luck.
It is only a matter of time before the battery dies:frown:

Any other ideas? Any help would really be appreciated

I have this issue, I fix it as follows. Car won't start, turn key all the way off, then all the way back on. Security light will flash for 10-20 min, mine is usually always 12 min. When the light stops flashing and dissappears, turn the key ALL the way off then all the way on and start it up. I make sure I get gas when the stoopid thing won't make me late for anything lol.

i;ve had the same problems over the last 6 months.at first it was just intermitant no starts. and got worse finally bit the bullit and bought a new ignition cyclinder.solved the problem for a few days with no more security light flashing but still random no starts.so traded the truck to the old girl and i got to deal with the POS.
Then a funny thing i had noticed an oil leak over the same 6 months so i finally investigated it and it was the oil pressure switch.pain in the a## to change. but did after that i've had no problems starting going on 6 weeks now. can't say for sure if that was the problem or i just bumped a wire when i was under there.
So maybe have a good look around under the hood and check for loose wires or conectors or anything that dosen't seem good. as everything is conected together to allow the car to run.

Hope my two cents helps

Cheers Paul:iceslolan

thanks for the replies!

I am going to swap out the ignition cylinder and see if that helps.

It is possible to trick the computer to disable the passlockbut your theft light will stay on. You would have to snip the solid yellow wire on the BCM under the glove box on the middle connector while the car is running. Let it run for a minuite and then install a switch somewhere for that yellow wire, so that if you swap out the battery or kill the battery you can switch that yellow wire back on quickly. I snipped mine and its been excellent ever since, now I have to figure out how to remove the theft light bulb! LOL

It is possible to trick the computer to disable the passlockbut your theft light will stay on. You would have to snip the solid yellow wire on the BCM under the glove box on the middle connector while the car is running. Let it run for a minuite and then install a switch somewhere for that yellow wire, so that if you swap out the battery or kill the battery you can switch that yellow wire back on quickly. I snipped mine and its been excellent ever since, now I have to figure out how to remove the theft light bulb! LOL

Have fun until your car's battery goes completely dead and your passlock decoder completely fails. When that happens you can make your vehicle into a nice yard planter since you'll never drive it again.


The best and cheapest way to completely fix this is to do the following.....

Tools: Ohm meter, wire strippers, wire crimpers, needed resistance value in resistors.

Get behind the ignition switch. See large harness going to ignition switch. Open up that harness and you should see a bunch of large gauge wires. Look closely and you should see 3 tiny ones (yellow, black, and white). Grab the black and yellow wires. Start the car (hopefully security goes off). Cut yellow wire and meter the cut end that's toward the ignition switch and the black wire. Then meter that cut yellow wire again but next put the other lead of the meter to chassis ground. Which ever value is higher get a resistor(s) that closely match that number you got when you metered those wires. Take the OTHER end of the cut yellow wire and install the resistor to it and then to the black wire or chassis ground. Shut car off and start it. Light should go out. If the car starts then stalls, you may need to adjust the resistance value. If security light is on, verify that you have the correct end of the yellow wire attached to the resistor. If so, it should go out on its own after a while.

If your light was on steady before doing this repair and is still on, you may need to do the relearn sequence UNDERSCORE stated. This is the ONLY way to disable this system and not have to worry if your car's battery goes dead.

Here is a method for removing the Security light from the cluster: http://www.oldsmobileforum.com/forum/showthread.php?t=1194

Read to the end of the first post.

You gotta be careful on some of the GM lines because they need to "see" that bulb in the cluster. Without it, even if the PK2 system is fine the car may not start. That's what the white wire is with the actual black and yellow PK2 wires.

Ok so if the passlock does screw up and the theft light comes on, what does it shut down exactly? If it is just the fuel pump, could you not power that relay to bypass it or does it shut down a few things?

No, everyone says and thinks it shuts off the fuelpump but it actually turns off the fuel injectors.

I have this issue, I fix it as follows. Car won't start, turn key all the way off, then all the way back on. Security light will flash for 10-20 min, mine is usually always 12 min. When the light stops flashing and dissappears, turn the key ALL the way off then all the way on and start it up. I make sure I get gas when the stoopid thing won't make me late for anything lol.

I got the same problem with my Alero today.
Thanks to your advice and my car is fixed using the method above.

Have fun until your car's battery goes completely dead and your passlock decoder completely fails. When that happens you can make your vehicle into a nice yard planter since you'll never drive it again.


The best and cheapest way to completely fix this is to do the following.....

Tools: Ohm meter, wire strippers, wire crimpers, needed resistance value in resistors.

Get behind the ignition switch. See large harness going to ignition switch. Open up that harness and you should see a bunch of large gauge wires. Look closely and you should see 3 tiny ones (yellow, black, and white). Grab the black and yellow wires. Start the car (hopefully security goes off). Cut yellow wire and meter the cut end that's toward the ignition switch and the black wire. Then meter that cut yellow wire again but next put the other lead of the meter to chassis ground. Which ever value is higher get a resistor(s) that closely match that number you got when you metered those wires. Take the OTHER end of the cut yellow wire and install the resistor to it and then to the black wire or chassis ground. Shut car off and start it. Light should go out. If the car starts then stalls, you may need to adjust the resistance value. If security light is on, verify that you have the correct end of the yellow wire attached to the resistor. If so, it should go out on its own after a while.

If your light was on steady before doing this repair and is still on, you may need to do the relearn sequence UNDERSCORE stated. This is the ONLY way to disable this system and not have to worry if your car's battery goes dead.

Hi. I am new at AF. I found it while searching for the reason why the Security-light of my 1999 Alero kept shining. Then I found ponchonutty´s post and went to work.
After an almost complete tear down of my car (or so it seemed) I found the three wires (yellow, black, white), so I guess my car has a passlock I-system. I cut the yellow wire and now I´m in deep trouble since the car wont start at all. I´ve read various posts in different forums, saying that the Security-light will shine but that the car should start without problems after that.
Since that is not the case with my car I´m rather desperate and would really appreciate any kind of help. I hope that when everything else fails I can still reconnect the two ends of the yellow wire to return to the former state and then buy a new ignition swith/lock cylinder.

Thank you,
Stefan

You must install the resistors as mentioned above after cutting the yellow wire, or the car will think a theft is occurring, and will not start.

Okay. Seems that even though I read everything I didn´t fully understand it. Thank you very much
Stefan

Hello, it´s me again. I obviously don´t get it. I made the measurements as described by ponchonutty at the correct wire ends (that´s the part I had no problems with). There I ran into trouble for the first time:
1. meter: yellow (ign. end) to black => 1495 Ohm, yellow (ign. end) to chassis => Nothing, nada, zero, Null.
2. meter (lucky me I had another one!): y to bl => 1467 Ohm, y to ch => ~ 990 Ohm
Second measurement: y zo bl => 1370 or so, y to ch around 990
Let´s say I get a correct resistor measurement so I can proceed. As far as I understand it I have to follow these steps (Security isn´t on right now, problem just began to show):
1. Disconnect (= cut) the yellow wire while the engine is running.
2. Let it run for a few minutes, then turn engine off.
3. Connect the black wire with the far (i.e. non-ignition) end of the yellow wire.
I hope that there are no mistakes until here, because from here on I´m not sure what to do: Do I have to "relearn" my BCM to know the (non-existant) key in the lock or does it assume the key is in the lock because of the same resistor value?
If I have to relearn, does that mean 10 min. ignition ON, 10 min. ignition OFF, then start the engine? What is the SECURITY-light supposed to do during this process? Blink? Shine continuously?
I´m sure that for a reader with more and deeper knowledge than all the answers are already in this thread, but I would appreciate your help very much.
Thank you!
Stefan

Step 1. Have you cut the yellow wire? If not, you will not get the correct resistance. Cut the yellow wire with the car off. Then put the car in reverse with the engine off. Turn the key to start, and while the key is turned, measure from the ignition switch end of the yellow wire, to the uncut black wire. You may have to measure several times, and average the values. The car should not start during this process. I think mine measured about 1500 ohms, but they are all a little different.

Step 2. Attach resistors between the other end of the yellow wire (non-ignition end) and the black wire. The resistors will make the BCM think the correct key is in the ignition switch. After this, any key that will turn the switch will start the car. The ignition end of the yellow wire is not used anymore, wrap it up out of the way somewhere.
You may have to do the relearn procedure after this, I don't remember since it's been 3 years since I installed my resistors.
Hope this helps.

Thank you for the explanation! I will try it ASAP and post the result!
Stefan

iflylow & ponchonutty,

you are my heroes! After finally getting a correct mesurement for the resistors (hint: a k near Ohm means KILO; 930 Ohms aren´t the same as 9,30 kOhm, as I finally realized!) it was just a snap: I soldered the resistors in (2 x 4,7 kOhm), turned the key and everything was perfect. It wasn´t even necessary to do the relearning procedure.

Thank you for your invaluable help!
Stefan

Glad to help~