B2721 - PASS Key Bypass
Thread Starter
Instructor
Joined: Apr 2009
Posts: 198
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From: San Marcos TX
B2721 - PASS Key Bypass
I have been having the seemingly common B2721 and it looks like I have two options:
-Replace Ignition Cylinder.... and have the same problem sooner or later with the contacts wearing down
-Bypass the contacts by wiring in a resistor
How many of you have gone with the wired in resistor method? Just need to know how to find out which resistor I need and which wires send the signal back to the BCM.
-Replace Ignition Cylinder.... and have the same problem sooner or later with the contacts wearing down
-Bypass the contacts by wiring in a resistor
How many of you have gone with the wired in resistor method? Just need to know how to find out which resistor I need and which wires send the signal back to the BCM.
Tech Contributor
Joined: Oct 1999
Posts: 41,043
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From: Charlotte, NC (formerly Endicott, NY)
Why not try and clean the contacts on the keys and in the lock cylinder before jumping to conclusions. By using a resistor you are disabling the major theft deterrent feature of the car. This is not something that happens very often so even if the lock cylinder required replacing you could probably go for 20 or more years before this failure occurred again.
GM got all of the design problems in this feature debugged 22 years ago.
Bill
GM got all of the design problems in this feature debugged 22 years ago.
Bill
Thread Starter
Instructor
Joined: Apr 2009
Posts: 198
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From: San Marcos TX
I have cleaned the contacts on the keys and inside the ignition cylinder numerous times. I have three keys, one of which has never been used. Even after switching to the new key the code/problem is still there.
I have considered replacing the cylinder, but after reading multiple threads about the same problem, I thought the resistor might be a more permanent solution. Of course, problems always seem "common" when you're on the forums, so maybe I am reading too far into this.
My car is only 9 years old and has fairly low miles, so I wouldn't say they fixed all the bugs of the key pellet system 22 years ago.
I have considered replacing the cylinder, but after reading multiple threads about the same problem, I thought the resistor might be a more permanent solution. Of course, problems always seem "common" when you're on the forums, so maybe I am reading too far into this.
My car is only 9 years old and has fairly low miles, so I wouldn't say they fixed all the bugs of the key pellet system 22 years ago.
Last edited by dodriven; Jul 22, 2009 at 04:49 PM.
Tech Contributor
Joined: Dec 2006
Posts: 10,962
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From: Van Buren Arkansas
Wounded Warrior Escort '11
Well, if you do the resistor, insure its a high precision one but don't complain if someone comes along one day and rips off your car by simply jamming the ignition. Its your risk so do as you wish.
