Warner Robins, Georgia
Not resolved

This letter is addressed to General Motors.

Why are many of your vehicles experiencing vehicle "security light on" (random events) and "vehicle will not start" (random events)?

My 2003 Impala has experienced these issues over the past 2 years. The "security light on" (who really cares) but the issue with the "vehicle not starting" is really serious.

I have investigated many difficult problems in my lifetime... I like to explore things fully!

I have vast experience in Electronics, Engine control management systems and Auto repair.

Currently, I am working as an Embedded Software Engineer.

I have fully investigated the PassLock II issues "online" and have found such a large number of complains directly relating to my complaint.

What is staggering, is that many times, consumers take their vehicle to a certified GM dealership and pay for the repair (I've seen up to $450.00 posted).

A day or a week later the problem comes back...

Many consumers have simply defeated or by-passed the PassLock system. The information and kits are available by doing a simple search.

I would like 1% of the money GM dealerships have extracted from consumers regarding this issue!

Now here is some interesting news for GM and their dealerships.

I have personally investigated my PassLock problem from a serious technical view point.

The dash was tore apart and eventually, I was able to remove the ignition switch which has the Pass Lock (magnetic sensor system) mounted in it.

The ignition switch was dissasembled and I looked closely and observed a few interesting things about the PassLock system design.

1) The male connector does not fit securely in the female connector receptacle. It can wiggle up and down and back and forth.

2) The connection is a "blind connection" meaning that during assembly one would not know if the PassLock connector was connected correctly or not.

3) The male and female pins used on the PassLock system are "Tin" plated and subject to oxidation over time. The pins should have been "gold plated."

The grey oxidation was clearly visible under 10X magnification.

4) The Body Computer does not adjust over time for the oxidation that build up on the PassLock pins.

The critical analog PassLock signal drifts depending on mechnical issues, temperature and humidity.

Ok - GM -> The PassLock cat is out of the bag!

What I did about this problem.

I certainly did not take the vehicle to any GM Dealership and get "rear-ended."

I simply hand soldered the three wires (Black, White and Yellow) directly to the PassLock sensor.

The vehicle is repaired and I would like to let GM know that when I sell this vehicle, I will offer a "LifeTime Warranty" on the security system for this vehicle (more than you can do)!

So what is GM doing? Well, the Dealerships are collecting a lot of money from us. They, the Dealershipsr are simply replacing the sensor ($150.00).

Can all of these sensors be going bad? The answer is no...

When the sensor is replaced the oxidation on the female connector pin is temporarily scraped and makes a better connection. Three years down the road (guaranteed!) you will be up against the same issues.

So the "root cause" of this failure and GM's inability to permanently fix this problem is now understood.

When consumers are installing bypass kits they are not bypassing the Body Computer or the three required signals to the Powertrain Controller (Class II serial communications, Fuel Enable and Crank Enable) they are bypassing the sensor and the connector. The problem is with the connector and its pins!

OK -> GM and Dealerships wake up and return all of the money you've swindled from us! You use technology against consumers and we are sick and tired.

GM, I've seen your last quarterly report and it looks like "we the consumers" in "North America" will not have to be dealing with you for very much longer.

I wish you all the best of luck!

Dr Zach

Product or Service Mentioned: General Motors Fuel Pump.

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just to let you know i'm pretty sure I found the problem, I like everyone else replace everything and still had issues UNTIL I replaced the KEY!. dont get it copied, you have to go to the dealer and have a new one cut from your vin. It like everything else wears out too.


AND AND AND!!! only have the car key on the key ring in the ignition, take everything else off, weight is bad for these ignitions,


also have 2002 monte carlo, will not start due to faulty passlock system. you should have continued using your "LIKE A ROCK" song to advertise. my monte carlo just sits in the garage like a big piece of shot rock, cause it will not start.


I am have this same issue.....help me please!!!


I'm having the same problem, only happened once so far. Took the whole thing apart and he's right, it is the connector that goes into the cylinder lock. It clips into the housing but the cylinder lock just slides into the connector without being fastened properly, I pushed down on the pins to see if that would make a better connection, i'm going to try to find a new connector, mine is a 97 Malibu 3.1 L so that is still pretty good.


I am experiencing security light flashing and a clicking coming from not only under the steering wheel column but also a clicking coming from the passenger kick panel/computer...these episodes always seem to be occurring when the interior cabin temperature is extremely hot...symptoms include flashing or flickering headlights, flickering dome light, no cooling from the a/c, door lock switch not working, truck release button not working...after the car is cooler problems go away after a shut down and restart of the car....Could this be a bad BCM...? any input would be greatly appreciated...Thank You!


2000 impala LS doin this same weak *** ***. GM bogus as *** for not recalling this.

when i first turn the key i just turn it to on just to see what the instrument panel gone do first. if the gauges dont go to the level they're at i know the car is goin thru this ridiculous problem. i have to wiggle the key in and out the ignition until it "tricks" the security system and eventually she fires up. usually takes me about 5 mins.

before i figured this problem out i changed my fuel pump fuel pressure regulator got the car towed and all kinda ***. smh


I wish i could see a picture of what exactly you soldered. Krisfelt@yahoo.com


I have a 2004 Monte Carlo and the passlock issue is a very big problem.


Having problems with Passlock in my 2006 Colorado. Would like to see pics and instructions.




do you have picture on how to solder the sensor


You talk a good game but you have yet to post step by stem instructions how and what to clean, where are these pins located on a 1999 chevy Silverado? talk is cheap we need proof sir.


just got quoted about 350.00 for new key cylinder. Probably still won't work..


Ok Dr. Mack where are the step by step instructions, where are the video or pictues showing us few who are not as electronically gifted as you?


Doc I'm in fort valley I have the same problem


Dr Zach Thank you!!! there needs to be more people like you in this world! I have two sons one has 02 and other 05 its just not right for them to not recall the pins at least and cover the labor it seems they could careless after all these complaints and the saddest part of all there are people like me that bought CHEVY all my life and my family generations of chevy drivers dedicated I am a single mom thanks to a drunk driver and their father was a mechanic sharing your info to save me the money on such a costly repair I THANK YOU!!!


I love what you posted i have the same problem and no one will

help me find or help fix it i will never again buy gm i think i will stick to toyota much butter car over gm i hope gm goes down the tubes for this and to fix the problem i was told from dealer that wanted anywhere from 500 dollars to 1000 dollars to fix can anyone help me fix it as iam not good with these problems and i don't have a lot of money as i am out of work please can someone

help me or show me what to do thanks


Amen Dr. Zach.

I went thru all that rigamaroll w/ my 1999 Alero and know exactly what you're saying.

"Good luck" unfortunately will probably not be enough to save GM. Have been just too many of these kind of issues.

~Tom D., Valhalla, N.Y.


Thanks everyone. I did something a bit different on my Passlock II 1999 Chevy full size van.

Instead of the soldering job Dr. Zach did, I just cleaned the tiny three pin connector's contacts with muratic acid, and so far, it seems to have permanently worked. Tools used were wooden toothpicks, small bits of paper towel material, and very fine wire for the female connector.

Though there wasn't any visible corrosion on any of these contacts, even with a high powered magnifying glass, evidently there was some, that was hindering the very low voltage signal being transferred through this critical connector on the key lock cylinder sensor and three pin wire connector. Hope this helps someone - sure a lot easier than getting in there and soldering those extremely tiny, hard to access wires.

@Steve 777

Would you mind taking pictures of what you did so we all can be on the same page, all of us are not born again mechanics you know, it would be nice to see this hugh issue that is giving everyone including me all kinds of headaches. my e-mail is dvalleysr@yahoo.com if you decide to take some pictures and share this information with the rest of us?

Thank you

David Valley Sr

Houston, Texas