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 🙂

293 Comments

  1. As an ase and g.m. certified tech this sounds lacking. GM made 3 types of security systems…passkey With the resister in the key….passlock With a tumbler sensor on the ignition lock….and pk3 With a chip inside the key head and also referred to as an immobilizer system. The passkey can be bypassed with a resistor. The passlock used a relearn procedure. Furthermore, different cars use different color wires. So my questions to the author are…1. Are you saying a resistor can be used to bypass the paaslock sensor? I have never heard of that. 2. Are you saying that the passkey sometimes needs relearned after installing a resistor? I have never done that. Could it be that you are combining pieces of info about each system?

    1. Author

      1. An installed resistor replaces the factory resistor used by the passlock ignition cyclinder.

      2. A relearn is needed if you’re unable to match the stock resistance read by the ignition cyclinder.

      This not my schematic, but merely refference

  2. 2002 pontiac grand a m. followedproceedure cut yellow no luck. security lite stays on willnot start. if i drop neg. battery and wait for fifteen minutes hook it back up car starts.works good for me not so much for wife. any solutions?.thanks

  3. I have a 2006 escalade. I have red and white, orange and black, green and tan wires. No black wire. Please help.

    1. Same issue the colors do not match on the 2006 Escalade ESV. And it would be nice to have a plug and play module for the 3 wires so you wouldn’t have to cut or solder anything

  4. Will this work on a 2001 silverado 2500hd?

  5. Does not work on my 1998 grand am. I tried 4 Different values of resistors. When the key sensors fails the pass lock system will flash for 10 minutes and then you can retry. When I have the resistors in the circuit between the yellow and black wires at the sensor. The security light flashes 3 times once I try to start it and then goes back to steady lit. If I start the car while the sensor is working then unplug the sensor the security light comes on but I can start the car every time with out issues. However the light is on any time the car is on. Also step 6 give me no reading of the resistance it measures open. So I have to just try different resistors. I have been and electronics tech for more that 20 years so I am positive that I am using the meter correctly.

  6. Excellent info straight to the Point works great

  7. Has anyone ever tried to remove ignition and completely do away with the system? I have an old colom in going to pull off tomorrow and open it up..has to be a way to bypass it where you never have another issue

  8. If it dont work can i hook the yellow wire back up and will it start again

  9. I have a 01 blazer and cut the orange and black whire to hookup a 10k ohm resistor to the yellow wire and hooked it up to the black and orange whire…. Still not turning on and it immobilizes the car by cutting power I fuel pump as it’s meant to do…. How can I get it to not cut the power off to the fuel pump

    1. Don’t cut the orange black, cut the yellow wire.

  10. My 2006 grand prix was broke into and they tried to steal it . They tore the ignition out and the pk3 chip. I out the ignition back in and it won’t start due to theft system. The 3 wires that came into the chip were cut and now what do I hook the ohm reader up to? And is the bcm on the driver’s or passengers side ?

  11. Some GM vehicles have a Key sense wire that must receive a ground signal to indicate the key is in the ignition. without it grounded the security light will activate but I believe the car will still start. I’ve installed over 50 remote starters and I always have to ground the key sense wire or have a security light issue. Just thought this may be helpful.

  12. Have a 98 sunfire. Thank god I dont need to move my car for now. I need to bypass the passlock. Ignition switch is in the column. I have no clue about car wiring.

  13. I have a 2004 Alero and it will not start what do I do to bypass so the car will start for me

  14. I have a 97 Grand Am and done this and still the Theft light is on and won’t start as well as the shifter unable to come out of Park. Ideas?

  15. I have a 1996 Oldsmobile acheiva. I did what Jeremy says above about 3 years ago. I started the vehicle and cut the yellow wire. Then turned it off. All was good for a couple years. Then it started going into lock again. I would reconnect the wires and get it to start and pull the wires apart and turn the ignition off before it died and it was good for a while again. Now it’s completely dead. No start and stall at all. Ca not do the factory reset either. FYI I’m a life long mechanic/electrician. This one has me wanting to power the fuel pump and the coils some how and over ride the system. I’ll try the resistor first.

  16. Have a 2000 Chev Van 3500. Need to bypass passlock sensor. No Chip in key

  17. Here’s an easy way to disable and/or remove the system:

    1. Make sure engine is running. Purposely cause a fault in the system. I find the easiest way to do this is to unplug the BCM.

    2. Security light should pop on. Next, either unplug the sensor or cut the wires going to it.

    3. At this point you can turn the engine off. Plug your BCM back in, either tape over or remove the security LED, and you’re done. You can leave everything in or tear it all out at this point.

    1. Hi I have a 98 chevy Silverado vortec 5.7 k1500.Ibe tried using resistors, I replaced the passlock computer module and doing the relearn proceeder at each attempt.thr security light stays on.the truck will start run for two seconds and die

  18. have 2000 astro van how do i bypass the pass lock sys

  19. What exactly do u mean by find a resistor of equal or close to same ohms?

  20. 1998 s10 security light comes on and no fuel sent to cylinders. I want to bypass system. What is my cheapest option?
    This morning I jumped on the bumper and rolled it back a few feet like a wrecker picked it up again and the truck started. Just don’t want to be stranded. Thank you in advance.

  21. my sunfire doesnt start! the theft system is actived, i connect a switch between orange and black cable and the theft system continuos, what i need to do for to engine start?
    Thank you!!

  22. I replaced my ignition switch and the lock cylinder was put in upside down so when I hooked up the battery the black wire on the clip opposite of ignition switch by the firewall fried and now it lights up but just clicks where do I run new wire

  23. I cut the yellow wire and spliced the black wires leading up to the sensor that plugs into the ignition housing and connected my ohm meter to the black and the yellow end that goes to the ignition sensor and turned the key to the on position and get no reading on the meter. do you have any idea why or is it not connected correctly

  24. will this work on a 1999 gmc 1500 sierra 4.3 pickup. unhooked the battery and changed the fuel lines going to the spider’ Hooked everything back up and it will not start Code is saying security fuel shutoff. Fuel pump is working fine,

    1. Thank you for the info.I also own a 99 sierra. rent the Bosch unit from auto parts store this will let you start your truck then pull all three wires from top of the key cylinder I did this and it has started every time for a year now.

  25. 04 pontiac grand prix gt bypass theft system for ignition switch

  26. I did this on my 2002 Saturn. The resistance was 559 ohms so I tried 1000 ohm. It worked on the 3rd try. I checked the service manual and it says to use the 30 minute relearn procedure (3-10 minute) if you don’t have the scan tool. Thanks for the info.

  27. On my 2001 chevy pontiac sunfire, the radio was hooked up wrong so I fixed it, and when I did it sent the car into theft mood. So I went and disabled the Orange and black wire and grounded it out to see if I could get it to start. And now it starts then shuts off, its like it’s not getting any gas I don’t know if it’s still in theft mood or what but if any one has any suggestions if you could text cause I kinda need it fixed tomorrow. 9795307610 thank you.

    1. Change your ignition control module.make sure its programmed

  28. I have an 06 impala and my wire colors are black,white/black,pink,purple/white and white so I don’t know which wires to cut.
    please help thank you.

  29. I have a1999 Yukon Denali.. I cut the yellow wire on the ignition but i’m not getting a resistance reading. The ignition has been replaced.. Any idea why i’m not getting a reading??

  30. Wat if egnition is ripped out how would I by pass anti theft systenlm

  31. If I am getting no ohms is the bcm bad

  32. Will this work if the computer has shut down the fuel pump? IF not what do I need to do? I can get the car to run. If I unhook the pump at the tank and put a jumper on the pins and put power to it

  33. My question is will this still work if i dont have the factory radio installed. Right now i have no radio, everything works but the anti theft problem.

  34. Ok i got a 2000 gmc seara sle put a single 680 ohm in pass key code wire yellow to black live end to comp.and put same one to purple and yellow on pass.side kick pannel..why wont it stay running..? Please help..this is a contest to me to learn this and realy wanto sucseed..help asap.advice to try..?


  35. I have a 2004 Yukon XL 2500 4WD. Will this procedure work for this vehicle?

  36. Ok I tried everything you suggested. I even bought a new ohm meter to be sure and tested it. I have ZERO reading from the black to the yellow key wire or computer wire on my 2003 1500 2wd 5.3 suburban. It won’t start no matter what I do.

  37. I put a 6.14 resistor in the truck 2003 suburban 5.3, from the yellow to the module to the black (uncut) I have done the relearn twice now and still no start. The light still flashes when I try to start the vehicle. I see a .05 2.2k resistor has worked for others. Is my problem the resistor value? I will try one more relearn as I see another person had to do it three times on a 2004 Yukon which is basically the same as my Suburban. Thanks for your help and I hope you can answer me soon.

    1. I’m not sure about your Suburban but I was told for the 2005 trailblazer with the 4.2 L I-6 that the relearn process is actually 3 x the 10min procedure above and make sure you do the last part of it to the Tee

  38. Just tried this and it removes the light but still will not start. ? I did it exactly as you stated? Any suggestions?

  39. What is my probe my vehicle has the group 1 set of wires.

  40. Switch completely locked on my yukonxl 2003

  41. I need help with my cavalier if you can help me contact me (phone number removed) my name is Weldon I have a 1996 Chevy cavalier 2.2L theft lock on

  42. Have the same problem on my car 04 impala witch security wire it is

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.