Pass Lock II is used on many GM vehicles from 1995-2005 and can be identified by a security light on the dash and by an ignition key with a “PK2” stamped on the metal part of the key where it meets the plastic end. There are some keys that may not have the “PK2” stamped on them and are also used for this system. These keys only function to turn a lock cylinder that houses a magnet in the center of the key cylinder assembly

(Figure 1) .

When the lock cylinder is rotated in the crank mode it will travel far enough for the magnet to go past the sensing device allowing the sensor to send a signal to the security module.

The sensing device is a 3-wire Hall Effect sensor

(Figure 2)

that the security module feeds a referance ground and referance power on 2 of the wires. The 3rd wire is a 5V referance signal line from the security module that the sensor will pull to a certain level when the magnet passes the sensing device. The hall sensors each have their own unique end result value between 0.5-4.5 volts when pulling the 5V ref low and this value will be learned by the security module and kept in its memory. When the battery goes dead or a new hall sensor is replaced you will need to relearn the Pass Lock sensor value into the security module.

The learn procedure is as follows:

Turn the lock cylinder all the way to the crank mode so the magnet on the lock cylinder can travel pass the Pass Lock sensor. Now let go of the key so it can return to the run position. The 5 Volt line will now be pulled to a value below 5 volts and the security light may begin to start flashing or just remain on solid. Some vehicles may start up and stall or may not crank at all. You must leave the ignition key on for 10 minutes and place a battery charger on the battery if needed in case the battery is low on charge. After 10 minutes you will see the security light go out or just stop flashing and then go out. At this point you turn the key off for 5 seconds. After 5 seconds you turn the lock cylinder to the crank position again to repeat the same process .You must perform this process 3 times for a total of 30 minutes of wait time. On your 4th attempt the vehicle should start up and continue to run.

 

Thanks Derf. I just saw and read your sticky from the forum main page. I wasn’t trying to start the car with each cycle, just turned it to the “run” position. Hopefully that works good me. In doing tre passlock bypass to see if that fixes my shut off issue and install the 2002 BCM. Then if all gutted well, install the remote starter kit I have. Then i can skip the dealer for a reprogramming. I’ll let you know what happens.

Jordan

 

I am beyond excited!

So I finally got around to taking the time to tackling the VUE and see if I can get her to run right. I installed the ECU and BCM from the 2002 Saturn VUE from the U-pull (that I have the cylinder heads from). I then installed a 2370 Ohm resistor for the pass-lock system then did the 30 minute relearn procedure. I didn't NOT realize in my previous attempts that i needed to attempt to crank the car over every 10 minute cycle, instead i was just turning the key to the "RUN" position. But it worked! She fired up on the third cycle and there are no lights, the horn works, it only had 3K miles less than what my car had originally, so that's a plus. But the main thrill was when drove it around for 30 minutes without any issues! I sat in the driveway and fluttered the throttle and it didn't stall out either. But I drove hard, soft, and everything in between without issue and it was great!

Thank you so much to Derf who worked with me on this and bounced not only his ideas on the issue, but listened to mine as well. I hope that one day i can return the gesture with someone that needs help.

Now to install a remote start so I can get my unlock/lock functions back and also gain remote start for those cold Michigan days. Then I have the entire front suspension, exhaust, subwoofer, amp bypass, and try to slow the rust under the car. But other than than that i am almost done

After all the work I am still at a tossup as to what the actual problem was, but I think it was a combination of all the three components failing together. The ECU was the issue for the fluttering throttle stalling issue. The BCM was the problem obviously for the ABS light, horn ground fault, and the random shutting down. Combine that with a pass-lock sensor that was failing, i think it just made a recipe for frustration. I did find it odd that the pass-lock light was flashing and going solid with the old components when trying to do the 30 minute relearn and now it was blinking and going solid with the new components. Luckily, the donor car was off the road because of rusted out rear upper control arm and not mechanical issues.

So thank you again I appreciate all the help :-)

Jordan

 

Jordan,
Few things make me happier than helping people to get their Sattys back on the road. Sometimes it's simple. Sometimes it most definitely is not.

Failure of multiple computer systems can be subtle, in your face, or both at the same time. Troubleshooting one thing at a time is the only way to find your way through the maze, and even then you have to decide what the next logical step is when you reach a fork in the road.

The important part is that your vehicle now runs. I'm sure there were a few missteps taken along the diagnostic process, but that comes along with free help, at least from me.

I'm going to guess the previous owner said the timing belt was about to break because he knew the car had issues he could not fix, but did not want to actually tell you what they were or have you experience them on a test drive because you would never buy the car. So he told you it was something mechanical that is easily fixed. Not the computer electrical nightmare it actually was.

When I come across people like this in life, it is almost impossible for me not to kill them with kindness. I try in general to take the high road,

In this case, I would call ahead and ask if you could ask a few tech questions over a beer, then stop by his house on the weekend driving the car. Thank him again for the vehicle and tell him that it wasn't actually the timing belt. Tell him 2 of the spark plug wires were bad and the ignition switch wire to the starter relay was partially broken. Then ask him about the suspension......

You know it's not true, he knows it's not true, but he can't say a word. And he doesn't get to know how you fixed it. Conning the con.

What goes around comes around.

Enjoy your ride.

Derf

 

I learned a long time ago to not buy computers or engines from a car with no obvious problem. Thanks Derf for working through this!