Print Page | Close Window

Resistor Bypass, 2004 Buick Century

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=100409
Printed Date: July 19, 2025 at 12:31 PM


Topic: Resistor Bypass, 2004 Buick Century

Posted By: tools
Subject: Resistor Bypass, 2004 Buick Century
Date Posted: December 25, 2007 at 8:18 AM

Been reading this site and its EXCELLENT,some one on here said that on a VATS system,(mine is on a 2004 Buick Century) that one could cut the wires that goes to the ignition switch chip in key, and tie in a resister of the same value as the key chip across these 2 wires that go towards the car and just leave the 2 ends that go to the key switch just hanging,that effectivly will bypass the alarm system (which I dont need an alarm anyway), A couple of questions about this, am I right in assuming that if BEFORE one cuts this wire, that if one left the key in the ignition, that the alarm is shut off and the remote start will work, or is there something else that will forbid the remote to start, Also, could I just tie a resister across these 2 wires without cutting them.



Replies:

Posted By: tedmond
Date Posted: December 25, 2007 at 8:59 AM

the buick has a VATS system. as for bypassing it. I wouldnt recomend disabling the whole fuel pump kill. The vats system is a resistor based system that when the resistance is met, the car can start. Technically, placing a resistor in, is NOT bypass the ALARM. placing a resistor will allow it to start without the key(immobilzer). if your planning to do a remote start, i suggest you pick up a relay to allow the system to be bypassed for the remote start sequence only. NOT bypass it COMPLETELY. if it was bypass completely, someone that copied you keyyy can even start it.





Posted By: tools
Date Posted: December 25, 2007 at 9:37 AM

Please dont take this the wrong way,I do thank you for taking the time to reply, Im not being sarcastic or being a smart a$%^ ,but wether I use a resister alone or a resister and a relay is irelevant in my situation, Im well aware of what your talking about but its not what I asked. No offence intended and none taken.

I do have another question to go along with the two i asked in my above post,does the resister value have to be the exact value as the resister (chip) in the key or is there a little leeway up or down.

Thanks.





Posted By: another-kelly
Date Posted: December 25, 2007 at 11:25 AM
you have a bit of tolerance (usually the 10% tolerance that most resistors are), but try to get as close as you can




Posted By: tedmond
Date Posted: December 25, 2007 at 12:03 PM

the reistance can have + or - value of 5% only. any lower or higher will cause the theft system to go into tamper mode for 15 min.

as for cutting wires, you will see a black or orange loom running down your ingition barrel.  inside the loom there will be 2 white or a white and purple i beleive. you will have to cut the one that shows a postive reading. as you mentioned something about placing a key into the ignition, your on the right track. What happens is, you must start the car, and while the resistance has already been met and the car has starter, you may THEN Cut the required wire, then wire in your resistor.

to get the resistance off the key, grab a DMM (digital volt meter)

set the DMM to read 20 or 200 ohms. take your key and place it on a surface so the key stands up or so its easiest for you. on the key towards the handle, there is a black pellet with 2 metal shafts on each side. take the neg and pos test lead, place one on each side and see what resistance it will give you. make sure u dont touch the key(metal) because it will throw your numbers off. From there get a resistor or a POT and adjust it accordingly. the pot or resistor  will sit on the VATS line that shows (+) when the key is in the ignition. Check downloads section and search "VATS" there will a digram you can follow with a resistor and relay to bypass the system for RS or completely.





Posted By: techman93
Date Posted: December 25, 2007 at 12:42 PM
Try to get as close as possible in value. I would stay within 5% to play it safe.
I have to admit we installers hate the anti-theft thing but people who buy cars just want a little security knowing their car is a tad safer then one without. Not by that much and a pain to integrate remote starters to.

-------------
The wire I'm test'n isn't doin' what it's supposed to be doin'... I am so glad I printed that tech sheet, with the wrong info.
Do it right the first time... or I might have to fix it for ya




Posted By: tedmond
Date Posted: December 25, 2007 at 2:28 PM
cant agree more techman. i think Passlock systems are a PITA IMO. well they used to be, now with the data interfaced bypass, there is less headaches phew !





Print Page | Close Window