need advice for bypassing passlock 2

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=127216
Printed Date: May 18, 2025 at 11:00 AM

Topic: need advice for bypassing passlock 2

Posted By: morningrise8
Subject: need advice for bypassing passlock 2
Date Posted: May 04, 2011 at 9:04 AM

Hi everyone!

I own a 2001 Malibu with the Passlock 2 system, and I am having the INFAMOUS "theft system" issue.

I think I'm going to try doing the resistor method to bypassing this, but I am in need of some advice, as I've been doing a lot of research on forums, and have found some contradictory information.

I found a guide online that looks pretty thorough, and has photos:https://www.bergerweb.net/AleroSecurity/index.shtml

The big question for me is that in this guide he specifically says to DISCONNECT the battery before attempting this resistor install. Yet in many places people have said to cut the yellow wire WHILE the engine is running. Does anyone have experience with this type of install, and can give me some insight before I screw up my car more? posted_image

Thanks everyone!

Replies:

Posted By: blanx218
Date Posted: May 04, 2011 at 2:08 PM

You don't need to disconnect the battery. You'll need ignition power to measure your resistance value. With the car off, cut the yellow wire and strip back the coating on the black(or on some cars orange black) passlock ground wire. Put the E-brake on. Turn the key on and put the car in reverse. Using a DMM set on resistance or ohms, whatever yours says, measure the resistance by puttin the red lead on the ignition side of the yellow wire and the black lead on the black passlock ground wire, then turn and hold the key in the start position til you get a reading. Reverse the red and black leads and do it again. take the average of the 2 readings and find yourself a resistor to match with 5%. Then wire that resistor up to a relay.

Posted By: morningrise8
Date Posted: May 04, 2011 at 2:23 PM

Thanks for the response. Do I need to use a relay? I've read lots saying you don't need one...

Posted By: blanx218
Date Posted: May 04, 2011 at 2:46 PM

You don't "HAVE" to use a relay, but I would strongly recommend it. To wire it up, connect is as follows:

pin 86 to the Pink Ignition wire

pin 85 & 87 to black passlock ground.

pin 30 to the car side of the yellow passlock wire with the resistor inline

Use a standard automotive relay rated 30Amps or higher

Posted By: morningrise8
Date Posted: May 04, 2011 at 2:56 PM

Pardon my ignorance, (as I am clearly new to this), but could you briefly explain why the relay would make a difference?

I'm just trying to understand this. Thanks for your patience!

Posted By: blanx218
Date Posted: May 04, 2011 at 3:08 PM

The relay would prevent a feedback to the PCM. If you use a resistor straight to ground the PCM will see it all the time, sometimes resulting in a dead battery if the car sits too long without being driven(basically, PCM is always on and working) The relay only sends the resistance when the key is on therefore allowing the PCM to "go to sleep" like it wants too when the ignitions off. Its kinda like leaving your computer on all the time versus shutting it down periodically. No shut downs = eventually having problems.

Posted By: morningrise8
Date Posted: May 04, 2011 at 6:15 PM

While I'm on this topic. I have another question for anyone that may be able to assist.

The entire winter, my theft light was on, meaning that the system is obviously disabled. Since the warm weather hit, the light went off and I'm experiencing all these startup issues again.

Any idea?