engine swaps and passlockII bypass
Printed From: the12volt.com
Forum Name: Car Security and Convenience
Forum Discription: Car Alarms, Keyless Entries, Remote Starters, Immobilizer Bypasses, Sensors, Door Locks, Window Modules, Heated Mirrors, Heated Seats, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=15350
Printed Date: July 28, 2025 at 3:56 AM
Topic: engine swaps and passlockII bypass
Posted By: popeye2003
Subject: engine swaps and passlockII bypass
Date Posted: June 23, 2003 at 8:30 PM
Hello
I hope someone can help me please?
I have been looking on the internet at several different passlockII bypass systems and the 555L is the only one I have come across that interfaces directly (via the OBDII connector) to the serial data bus. The reason this MIGHT be important to me is that I'm trying to put a 4.3L V6 from a 2000 GMC Jimmy into a older model Toyota pickup. I purchased the engine from a junkyard and I got the engine, engine control module and the body control module but I failed to get the key cylinder so I do not know the resistor code of the key cylinder. The doner truck is scraped now. What I'm wondering is does the transponder- when connected to the OBDII connector learn the resistor value directly from the body control module or from the key cylinder through the serial bus circuitry indirectly? If the transponder learns the resistor value from the body control module then my problem might be solved. I sure hope someone can help me as I might be up a creek without a paddle unless I can overcome the passlock system. Thanks in advance
Replies:
Posted By: Chris Luongo
Date Posted: June 23, 2003 at 10:51 PM
The 555L does not go anywhere near the OBDII plug. The resistance wire coming off the key cylinder is cut in half, and the 555L is wired inline...when the car is started with the key, the 555L "learns" the resistance value, and then replicates it next time the car is remote started.
I believe some of the modules at www.transponderbypass.com tie into the databus. You might be able to learn something about how they operate by downloading the install manual, and reading the programming instructions.
According to a Saturn tech I work with, you can easily reprogram the PCM to accept any resistor value you want, either with or without a dealership scan tool. And I saw it in the service manual too. I'm pretty sure I remember the procedure, but I could be mistaken.
1. Install replacement keylock cylinder. (Or in your case, wire in a resistor.)
2. Turn the key to Run, and then very quickly bump it to the Start position. Don't actually start the engine, though. Let it sit like this for ten minutes.
3. Repeat Step 2 TWICE. The system should now be programmed to the resistor value you chose.
You should be able to look this up if you can get access to a factory service manual for any Passlock II-equipped GM car. There will basically be a section on what you have to do if you've replaced a faulty ignition lock with a new one---it'll tell you the procedure for reprogramming.
Posted By: BulletTooth
Date Posted: June 27, 2003 at 11:26 PM
Chris could you double check on the procedure and let me know how it is exactly done, I have somewhat of a similar problem , so if you can post or E-mail me the exact procedure it would be greatly appreciated. And popeye2003 if you found a solution to your problem could you share it with us. Thanks a lot my E-mail is (fmmahadin@hotmail.com)
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