Posted on by John Bain

How To Permanently Disable GM PassLock System

Purpose

The following instructions will allow you to disable the PassLock security in quite a few GM Vehicles.

  • This will allow you to install a remote starter and not have to purchase a bypass.
  • Avoid Costly repairs for an already broken Pass Lock System.
  • Disable Pass Lock system to prevent from being stranded in the future (or try Master Locksmith of New Orleans).

Requirements

A digital ohm meter (optional)
T25 Screw Driver (optional)
Alligator Clips (optional)
Screw driver or other tools for removing interior panels
1/4″ Drive 7mm or 9/32 socket and socket driver

Procedure:

 This tutorial varies depending if the ignition is located:

On the dash close to the radio

dashmounted

Is mounted in the steering column

steering_column

If your ignition is located in the dash then you will be removing the panels on the passenger underside (toe board) of the dash. The BCM (Body Control Module) is there and so are the wires we need to get too.

If you ignition is located in the steering column then you will be removing the driver side kick panels of the dash AND the clam shell around the ignition held in with torx screws.

For Cavalier and Sunfire Owners you ONLY have to remove the clam shell around the ignition that’s held in with 3 bolts.

Depending on the vehicle we will be looking for 3 wires bundled together their colours are either:

(Group1)Red/White Yellow Black
(Group 2)Red/White Yellow Orange/Black
  1. Remove the appropriate dash panels to get to the wire harness.
  2. Locate the Pass Lock 2 Wires, they will be coming out of the ignition OR on the BCM they will be located in the grey connector, Pin A6 is your yellow wire, and pin B6 will be a black wire(they should be right beside each other).
  3. Strip some of the wire insulation off the black wire, leaving it bare so you can test and solder to it later. DO NOT CUT THIS WIRE!
  4. Now cut the yellow wire, make sure to leave enough on both ends to give yourself something to work with. Strip both of the cut ends for testing.
  5. Take your digital ohm meter and put your negative probe on the black wire that you stripped back earlier. Put the positive probe on the yellow end of the wire that leads BACK to the ignition. Use alligator clips here to help the probes grab the wires.
  6. With the probes hooked up turn the ignition to the run position. Don’t try to actually start the vehicle, it won’t run anyways :). Read the ohm reading of the meter this is the resistance that we need to create to fool the PassLock security. Turn off the car.
  7. When selecting a resistance don’t worry about being dead on sometimes being close is good enough. If you can’t find something anywhere near to what you read on the ohm meter you have the option to use a resistor between 0.5K ohms up to 13.6K ohms.
  8. With the probes disconnected, take the resistor you selected and attach one of the ends to the black wire and then attach the other end to yellow wire that leads away from the ignition (goes to the computer).  Apply black electrical tape to the yellow wire end that goes to the ignition, we don’t need it anymore.
  9. With the resistor connected try and start your car, if you matched the resistance the car will start on the first or second try.
  10. If it starts then SUCCESS! Solder all your new connections. Tape up your bare wires and re-assemble your dash you’re done 🙂
  11. If it doesn’t start don’t freak out. You will have to do the factory relearn procedure(really easy)

10 Minute Learn Procedure 

  • Starting from the off position.
  • Attempt to start the engine, then release the key to Run position (vehicle will not start).
  • Observe the security light located in the instrument cluster, after approximately 10 minutes the security light will turn OFF. Turn OFF the ignition, and wait 5 seconds.
  • The vehicle is now ready to relearn the Passlock Sensor Data Code and/or passwords on the next ignition switch transition from OFF to CRANK.

Important
The vehicle learns the Passlock Sensor Data Code and/or resistance on the next ignition switch transition from OFF to CRANK. You must turn the ignition OFF before attempting to start the vehicle.

12.    Your all done, Solder all your new connections. Tape up your bare wires and re-assemble your dash you’re done 🙂

311 Replies to “How To Permanently Disable GM PassLock System”

  1. Tom,

    I have a 2003 Silverado 1500HD crewcab, and I’m having the same problems. Did you have any luck in fixing your problem, and if so what was the fix? Does your wireless remote (key fob) still work?
    Thanks,
    Jeff

  2. HELP!~ 98 cheyenne 2500 that’s had column replaced as well as cluster… anyway cranks, starts, dies every time! security light stays on – even after 10 minutes or 3 hours doesn’t matter never goes off tried the ohm meter to the 2 wires to determine the resistance and no reading ! so I went to the column where the wires come out of the switch and tried again, again no reading and yes my ohm meter is working so you think it’s the ignition switch itself or the uh…. gulp .. BCM?

  3. Recently did a bypass on my 2002 Impala to install a remote starter. Instead of this method, I used a relay, a 2.2k ohm resistor and just forced it to relearn that resistance. Both the yellow AND black wire are cut on the key side and not in use. Ran the (computer side) black wire to a ground, and the yellow wire to the relay. The “Ignition 2” wire is the switch, so it sends the resistance to the PCM while cranking, just as it would without the bypass.

    1. Probably also worth mentioning: I had to do the 30-minute relearn procedure. For those who don’t know, it’s the 10-minute relearn procedure done 3 times, back to back to back. So if the bypass didn’t work after doing the 10 minute relearn, try the 30-minute.

  4. This did not work on my 04 Monte. The security light was coming on intermittently, then one day it wouldn’t start – no crank, nothing. I was trying to determine if the cranking relay was clicking and it turned over and started after several tries. I then did this procedure. The first startup after doing this resulted in no warning lights and it ran fine. After about 5 minutes the security light came back on. Now it comes on everytime I start the car and stays on, but the car has not failed to start since.

  5. If you have the red white yellow orange and black is the orange and black the ground

  6. I have a 2001 chevy silverado 1500, been down for two years, would crank run shut stall, Ive tried everything but the passlock 2, im wondering if i should venture that route because nothing seems to work at all.

  7. FOR A 1998 GRAND AM I’ve TRIED CHANGING THE IGNTION FIRST AND THE RELEARN THAT DID’MNT WORK SO THEN I TRIED TO BY-PASS IT WITH A RESISTOR AND THAT DID’NT WORK EITHER ANY HELP ON THIS ONE

  8. I have an 2001 aurora. It was having starting issues. I suspect it was having passkey issues. In the mean time the only key I had for the car was stolen, so I went to the dealership and had a new key made for it. now the thing will not learn… the car is only worth maybe $1000 but I need to get this thing out of my driveway! any help would be great!!!! contact me at rdmorrow71@gmail.com

    1. I’m in the same boat what did u do the car runs fine and i just spent two hundred and alot of hours on fixing it so I need help if the passkey is out of the ignition will the ignition still turn the motor over and will it power all the rite shit and idk I got it to turn on ACC but no started today I charged battery and will attempt it again and if it works I’ll tell u but if not I jump starter it it works I tell u

  9. I will pay anyone in Missouri if they can fix my car!!!

    2003 Malibu with aftermarket radio not factory antitheft system siren goes off keyfob wont work if u pull the door handle all the doors unlock I have tried everything on google and youtube nothing works!! sometimes security light flashes stays steady or goes out car will not turn over just crank please help can some one walk me through this process please????? I HAVE 3 IGNITIONS AND ANOTHER BCM PLEASE HELP!!!!!! CONTACT ME AT tag.user@yahoo.com

    1. Hey, do the dashboard lights remain on when doing the key re-learning process? Ihave an 02 Malibu and for a while the car wouldn’t turn on, it would rotate but that’s was it. Anyways, turned out that one of the main fuses had a faulty connection. We spotted it by turning the key to the on position and then we jiggled the fuses a little bit. When the faulty fuse made good contact, the dashboard illuminate it and the car started. I would”ve never guessed that was my problem. We spotted the problem by accident!! Lol I was also in the process of doing the procedure shown on this website to the ignition switch but i think I did it wrong because the theft system light remained on but the car has been running ok for the past two months. Another thing I did is that I reinstalled the factory radio in it. Got the original wire harness and stereo at the junk yard, removed a chip from inside the radio to make it work. After market radios activate the theft system if they’re not installed properly so that’s why I went back to the original. I really don’t think the radio is the problem but I did it anyways. I hope any of this info helps so good luck.

  10. I have a 05 chevy Cavalier with a anti theft system that is locking my car up I need someone to help me figure out how to get my car started I thank you

    1. Maybe this will work: If the security light comes on when you try to start it, leave the switch in the run position for about ten minutes until the security light changes. Then turn the switch off, then try too start and leave switch on for another ten minutes until the light changes then repeat this procedure again (total of three times, takes about 30 minutes) then turn off and fourth try it might start. (worked on my 2003 Impala). Has something to do with the computer learning a new code.

  11. I wanted to greatly thank who ever posted this information, I just did this procedure to my car & it started right up…My car was down for 2 days due to this security. I went to radio shack, got me different resistors & place in & it started right up……You are truly heaven sent…Thank you so much for looking out for those that didn’t know what to do. Cause I wasn’t giving GM a dime…..I wish I could buy you dinner to a restaurant of your choice……Once again I thank you so much!!!!!!!!!!!!!!!!!!

  12. My 2003 Impala would not start and the security light would come on. After having the ignition switch cylinder replaced in 2009 at a cost of $431 and having both the ignition switch cylinder and the body control module (BCM) replaced in 2010 at a cost of $886 the problem returned again in 2013. I did this bypass procedure in 2013 and have had no further problems.

    1. Hey I have an 04 impala and need help. I don’t know which wire to cut because it’s so many harnesses around. Can you tell me what you did or show a diagram or pic?

  13. i have a 2001 gmc sierra 3500. could someone tell me what resistor i should use?
    the keys i have aren’t original.
    thanks
    Andre

  14. Will this work on an 08 saturn aura? My car just randomly completely shuts off a few minutes prior to shutting down that darn passlock light comes on, I figure if I disable it, voila problem solved

  15. Well I tried this because my car (02 Malibu) died on me on the highway and it wouldn’t turn on even after doind the 10 min steps. but in my case, I had a different problem. One of the main fuses wasn’t making good contact. When I had the key in the “on” position waiting to reset the anti_theft system, no lights appeared on the dashboard only anti-theft system light was on. So my dad pushed one of the fuses and all the warning lights came on and off like if something wasn’t making good contact. I pulled the fuse and it was fine. I opened the box thinking something was lose inside but all wires seemed tight and secure. I cleaned the two pins of the fuse with sand paper and used a small knife to clean the inside of the connector and finally pulled out a little bit the two pressure pins that secure the fuse to make it more tight and reinstalled the fuse. The car starts fine now. I was working on the bypass thing when we discovered that so I finished doing it but now the anti-theft light remains on but the car started after finishing so let’s see what happens. For now it seems fine and now I need to go back the first problem before the car wouldn’t start which was to find out why the cooling fans don’t turn on. First and Last Malibu I will ever own. Good luck guys.

    1. Make sure you’re doing it right. Also, there may be a problem with the sensor inside the ignition switch from where those three wires come from. I have replaced the ignition switch once in my 00 impala and that is sensor (i think is a sensor) connects inside the switch where the key makes contact with it. Getting a new switch was expensive but still cheaper than taking it to the dealer. I’m guessing that if there is no reading you may need to disassemble the ignition switch but I’m just guessing. Let’s see what the pros say.

  17. I have a 1999 Pontiac Sunfire and was wondering if I do all the steps to the wires coming out of the ignition lock cylinder black, white, yellow or is there wires on the left side of the steering column coming from the ignition switch not the cylinder that I am supposed to do the fore mentioned steps to. Please advise and thank you for this.

  18. I see that by the procedure you are using here is that the only thing being bypassed is the hall effect sensor in the column. this procedure is still using the Theft Module and the BCM to let the car start. A lot of these no starts are also caused by a defective Theft Module and this by itself will not go around that failure.

  20. If you have a bum BCM there is NOTHING you can do to get the vehicle Started AND RUNNING (vs. Crank-Start-Stall) UNTIL the BCM tells the PCM it’s OK to KEEP the Vehicle running…likely the problem for those of You having performed these “Pass-Lock II Bypass Procedures” where the vehicle STILL won’t Crank-Start-RUN : ?

  21. 1999/2000 chevy Silverado, computer was replaced and reprogramed. That didnt fix it so the ignition and harness were replaced next. It still has intermittant problems where it just wont start, turns over and fires but immediately died. The relearn process doesnt seem to work for this. Usually kill the batt trying to start it eventually and after some time, sometimes over a week if i jump it it starts. Then randomly it does it again. Does the computer need to be reprogramed since it got a new ignitiom and wire harness? Or can i just do this bypass to avoin this problem in the future, if the computer has to be reprogramed can i just do the bypass to avoid the $100 charge to reprogram it. 309,971 miles on original motor and tranny and counting!!!!

    1. I just repaired a ’01 Jimmy with the same-symptoms for having a bum BCM (actually had WRONG P/N installed)…and if you verify it comes pre-programmed you shouldn’t have to pay someone ELSE to do it, though you will need to do the 30 min. relearn proceedure, and possibly Remote Keyless Entry F.O.B. relearn too : ? Good Luck!

    2. Allen have a 2001 chevy 2500. Left key on. Charged batt tried relearn nothing. Not wanting to afford taking to dealer. How do you know if security, computer, ignition ect

  22. Thanks for the help I try everything from bypass module to whatever yours was the only one that work, truly greatfully

  23. Pingback: Passlock Bypass? - S-10 Forum

  24. I used the omhs resistors tried to reprogram it, and it still wont start. I can jump the starter relay it runs for about three seconds but shuts off, does anybody know what the hell is going on? Thanks

    1. The security system disables the fuel pump so car will start but runs out of fuel when the fuel line depressurizes.

  25. On the 04 Cavalier my bcm connectors are purple, blue and brown so what connector do I do this bypass with?

  27. I did this on my 2001 impala with a 2.2k resistor.Worked like a charm THANKS!!!!!!

    1. Hey… I’ve got a 2002 chevy impala… could you send me a picture of the finished product?

    2. Hey I have an 04 impala and don’t know which harness to cut the yellow wire from. Could you help me out? Where is the harness at that you used?

  28. My husband is trying to do this. Yes got the car to turn over and start but it shuts right back off. He also says the lights aren’t working. Guess it doesn’t help that he’s colorblind. Any suggestions as to what he might have done and how he can fix it?

    1. most likely he cut the wrong wire? women have much better color vision on the whole more then men do. so you could team up whith him on tis project and have some ‘quality time with him in the bargain. good luck.

  29. 2005 Kia amanti I removed BCM to clean connections .The windows wouldn’t roll down .After reinstalling BCM the windows worked fine . Drove the car about 15 mins pulled up to a stop sign and it quit .Started back up just wouldn’t idle .I noticed the car with the key in it on the dash was on . I know it has something to do with the security system .Any help you can give , it ran fine before i unplugged the BCM thanks Jerry

  30. Thank you !! after a year the car started right up. I didn’t even measure the resistance, I used the 2.2 that Toby C. ( above ) recommended and presto.. The transmission did remain locked for some reason until I performed one relearn system. My only question is the security light. The security light remains on constantly? should I reconnect the key side yellow wire to fix it or just live with it? which is no problem,,,
    Thanks again
    Pete

    1. Disconnect the battery for a few minutes. It should reset the security light. Make sure the black wire still goes to ignition

    2. wat kind of car did u do that on. i have an 02 monte carlo and cant seem to get it to work any help would b appreciated thanks jon

  31. Thank you, this is the best forum for this issue! I have finally found a quick fix and another option other than resistor/s. I went over to Radio Shack to buy some resistors and found an “adjustable Linear-Taper Potentiometer” I was able to adjust the resistance (0-5kOhm) until it was correct and after connecting it to the black wire and the yellow wire I adjusted it to the middle thinking it would be around 2.5kOhm and after adjusting it only a couple tries it turned over and started for the first time in over a year. Not to mention it was only $3.49 Check it out for yourself! http://www.radioshack.com/product/index.jsp?productId=2102789

      1. Did you ever figure out the wiring on the Potentiometer since it had 3 connectors?

  32. I have struggled with the pass lock on a 2004 Silverado, on which I replaced the pass lock assembly around the ignition to no avail. I figured out how to by pass the system by jumping the starter relay located in the fuse box under the hood ( made a jumper from a political sign wire, turn key on to run, remove relay, jump terminals 30 with 87, once started reinstall the relay ). This works well as I no longer get stranded until the truck restarts. But there were still issues especially with the vent controls not switching from defrost to dash vents as they should. I consulted with a local mechanic and he quickly stated that there is a data jam in the system and the fix is to remove both battery terminals, touch both together, then touch the positive to the negative battery terminal, wait a half hour or so, then reinstall the battery terminals (key out of ignition), finally perform the re-learn procedure (as described above). This has solved the vent control issues, now hopefully it resolves the intermitted starting issue.

    Chopper Don

    1. If you cut the wire while the car is runnning then it should disable the passlock but the security light will stay on till you repair the wire.

    2. Works on 01 cavilier! After trying resisters and adjustable POTS, I finally tried this! Put the two yellows back together did the security reset for 10 mins. When the light went off I started it up, while it was running I unhooked the yellow wires again. Car stayed running and starts up every time. Security light is on but I’m ok with that since it’s a derby car.

  34. I have a 2001 silverado 1500 ext cab 4 door 4.8 i went to start it and it didn’t do nothing just clicked i done the 30 minute relearn and it worked but i only got luck twice with it now it will not do anything i even went and bought a new key switch to put in it and done the 30 minute relearn and still nothing all my gauges work and everything else is fine any advice anyone i want my whole security system gone! thanks

  35. I just ripped apart the fuse control center under the hood and went and cut the green wire that goes for the relay for the fuel pump and ran that wire under the dash to the ignition wiring and tied that into but not cutting the gray wire and starts up fine never had a problem since. it bypasses the bcm and the neutral safety switch all together. the only thing that would make this not work is the oil pressure switch and the ignition switch wiring which are known to fail too but so much easier to diagnose. this was on a 2000 Gmc Jimmy 4×4 SLT

    1. I have tried the resistor bypass and no luck. I was wondering why there was not a way to turn the fuel pump on and bypass everything and then I read your post. Is the ignition wire you tied into grey on all gm’s. I have a 2000 Saturn.

  36. I found a wiring Diagram for my vehicle as I could not locate these wires where you said. I found a yellow wire in the BCM under pin A6 and a Blk/Wht wire under pin B6 but they aren’t in the gray connector however the yellow wire is the “security system sensor wire” and I also found in the gray connector under B7 a Tan wire that is “Security system sens low ref” and a blk/wht wire in B6 wich is ground. So my question is which of thwo security wires get cut? Tan or Yellow?

    1. Cut the Yellow wire, strip a bit of insulation to the Tan wire, wrap one end of resistor to it and the other end of resistor to Yellow wire leading to the wiring harness, and try to start the vehicle.

  37. Will this work on a 2006 Chevrolet Express van? If anyone has done it on this vehicle, what resistor should be used? I havn’t messed around with resistors before. Can email me back a response nick69chev@hotmail.com or post a reply on here. Thanks in advance for any help.

  38. Hi, I don’t want to install a remote starter and having security issues on my 2003 Chev. Siverado 1500 HD 6.0 engine, automatic, 4×4, with 4 doors. Will this work? I know its just passing the ignition and the problem could be the ECM. I’ve reprogrammed key fob and done the 30 minute trick. Both batteries are OK,checked engine grounds, starter wires, the solenoid on firewall and checked all fuses. Any imput or info greatly appreciated and thanks in advance.

    Tom

  39. hello. great write up. i am just unclear on whether the black wire is NEVER cut or just during testing and then cut to splice in the resistor. I can’t get the car to start with the resistor wired in. I did not cut the black wire however. Any help would be great in my troubleshooting process. Thank You.

    Bill

  40. Hello, I have a 2001 Chevy Tahoe, could you draw a diagram, since I do not really understand what and how and where to go and what to cut? Please, somebody on more detailed, with photos and diagrams to send me E-mail: 7_707_7@mail.ru

    I apologize for my English, I am from Russia! =))))

    1. Hey Toby, on that 2.2k ohms resistor for a GMC Disable Passlock System, what was the watts you used, because I have three types of 2.2k ohms resistors and they come in different watts, one is ⅛ watts, the other is ¼ watts, and ½ watts? I have a 99 GMC Suburban and gettin’ ready to do this, just need to know what watts to use…or does it make difference?

      1. Did you ever find out which wattage resistor to use Eli? I have the same vehicle and I have dumped over a grand trying to fix an intermittent starting issues with this vehicle which now points to this problem of possibly having something wrong with the PassLock system. Any info would be helpful regarding this fix.

        1. Buzz…I used a ¼ watt resistor, had to do a learn procedure, it took my vehicle almost 1.5 hours to reboot and learn, the security light stayed on the on position for 30 minutes then started flashing for about 45 minutes before it stopped and finally the vehicle started…gonna see if this works.

          1. Ok…update…I did the orange/black wire, the black wire, the black/white wire, the Gray wire to no avail, none seem to last or work until this last time, today as a matter of fact, I had the resistor connected to the Black wire for a week then, it would not start (did it twice this past week was almost late to work one day caught a ride), frustrated I researched a bit and saw Nick’s post (today down below a bit) and tried the Tan/White wire (my vehicle has a Tan/White wire)…Voila! it started right up! no relearn or nothing, after a morning of no start..So, it seems that the Tan/White wire is the one to connect the 2.2 Ohm ¼ watt resistor to the Yellow wire for my vehicle 1999 GMC Suburban, hopefully it will be the right one this time around, will be monitoring to see how long it lasts. This was very frustrating for us, the Pass-Lock feature is a Moronic Failure.

        2. I just left a new comment below, if you’re still having trouble. On 99 Suburban I used 2.2k / 0.5 watt and used the yellow and orange/black wires coming out of the ignition cylinder.

    4. Hey man , would this work on a chevrolet tahoe 2003? Could you help me with a diagrama if you have?

    5. On a 03 gm monte ,, we did the relearn, 2.2 k ohm resistor , had no reading of ohms between the wires like I have with other gms , so used 2.2k and relearn and worked. After about 10 days, the car seems to go into security mode anyway,flashing, then will not start, I take off the bat cables, short the two together,put them back on the battery, and it is good for another 10 days. I think the body control module, BCM is defective and needs replaced.Any advice?

  43. I have a 1996 pontiac grand am se 2.4L engine four door automatic.. I have tried your advice with a 10kohm resistor. at 1/t2 watt checked with ohm meter and the reading is < 10 with the ohm meter set at 20k prior to the install of the 10kohm resistor,the light continues to stay on after the gm relearn session has elapsed. please advise.

    1. GM requires you to perform 3- 10 minute intervals and after the 3rd attempt it will relearn the computer assuming that the security light turned off after interval ?

  44. Will this work for a 99 GMC Yukon? I’ve had to reset with the Key twice just to get it to start and I’m worried about messing up the computer system.

    1. I have a 2005 Saturn Relay Van with the same motor as your Malibu Classic. I am trying to replace the PCM and keep running into the Passlock security problem. Can you please tell me if you ever found out how to bypass or over-ride the Passlock system…THX! RKP_

  46. the 10 minuet wait did not seem to work at this time. I will try one more time and then go on to the meter trick

  48. this was awesome,,i finally slept,,,,i used a variable wattage resistor,,the one you turn volume up with.. worked great and i was right on the money,,please pat yourself on the back this was greatly appreciated more then you will ever know,, i finally got to sleep

    1. Hey, sorry to bother but my car hasn’t been able to start so I want to try using an potentiometer but I’m not sure which cable goes where. Could you help me. Let’s say I’m looking at the potentiometer from above and it has 3 pins counting from left to right, How do you wire?

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