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.
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
This tutorial varies depending if the ignition is located:
On the dash close to the radio
Is mounted in the 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:
- Remove the appropriate dash panels to get to the wire harness.
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).
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!
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.
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.
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.
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.
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.
With the resistor connected try and start your car, if you matched the resistance the car will start on the first or second try.
If it starts then SUCCESS! Solder all your new connections. Tape up your bare wires and re-assemble your dash you’re done 🙂
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.
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 🙂