Passlock II - 99 GMC Van

I am working on a 99 GMC Savana Diesel, that was an attempted theft vehicle. It has Remote start, Alarm, and a Passlock bypass module installed. Some of the wiring was damaged and modules removed by thief. The vehicle owner never used any of it because of lost remotes. My initial problem was a no crank and the security lamp on. I removed an in line fuse in a small gauge red wire and got it to turn over but I think the fuel is still cut off. At the request of the owner, I removed the entire system and returned wire connections to normal. I still get it to crank (no start) but now the security lamp flashes constantly with ignition on. Owners manual says it will start like this but service is required. I have a GM Tech2 factory scan tool and it shows a Passlock Tamper fault code. I know that the yellow passlock wire (at base of column harness connector) was cut (for the remote start) and since repaired. I tried the relearn procedure: key on 10 minutes, turn off when lamp flashes and back on for 10 etc. NO LUCK. The ignition key supplied may not be passlock type. Is there a way to bypass the passlock when it has already been triggered from the theft? I asked the owner to supply any spare keys he may have to try the relearn again.

This site is a great resource and contributors are to be commended for their help.

Bob

Bob,  your problem is not the key.  The key itself has nothing to do with the Passlock.  The resistor is inside the ignition switch cylinder.  Was the Ignition switch replaced in this vehicle after the theft recovery?  I would check the wiring and switch and check to make sure the resistance is still there and it is working properly.  I do not know the procedure for checking the Passlock,  but I do know how to bypass it!  :-)  Good Luck,

DanDan

Thanks for the reply Dan.

The thieves never got to the ignition lock cylinder so there was no damage evident. It looks like they tried through the remote starter wiring harness. I am now wondering if the original alarm/remote installer did a complete bypass and I disabled it when removing all the components/wiring?

I need to know how to get this baby running again. Should I re-install the passlock bypass module or? ( I don't know what make it is but I think it says Passlock 5 version 6.2 or something like that.)

THX

I would do a check on the Factory Passlock and see what resistance if any shows up.  I bet some damage was done somewhere.  Was the vehicle actually stolen or attempted?  Do not bypass the Passlock permanently.  I have never seen one fail and you will open yourself to theft.  You must of missed something.  Keep working on it.  Luckily you have the Gm's tech 2 tester.  I bet they are not cheap!

DanDan

 Tech2's are cheap enough if you get paid enough to use them!         $2600 U.S. per copy!

Current condition - Will Crank - Won't Run

The theft attempt was unsuccessful, only alarm modules unplugged and minor wiring damage no ignition lock damage. After further testing/checking today, I was able to get flashing security lamp off by doing the relearn procedure again with the Tech2 hooked up to monitor progress, but it immediately returned to flashing once the engine was cranked over. It still would not run! The owner shed some light on the alarm/remote system after these recent tests. He said that in order to start, left turn signal must be on. Since I removed all of the system, it should not be a factor (should it?). Is it possible there is another component I missed? I know some of you guys are pretty creative doing these installs. I took out the main control box, passlock bypass box, and what I figure was a starter kill box. I cannot see any more non-factory wiring. The weather hasn't helped with temperatures dropping and a cold diesel turning over slowly. We're going to move it into a warm bay when space allows. If no luck soon, sending it to Dealer.