GM Passlock I or II Disablement

You can do this without adding a remote starter.

PASSLOCK I or II DISABLEMENT

The following is a procedure to disable Passlock I or II Systems for vehicles in which remote start/stop system installations are required. This procedure is required because a remote start system will not function with the current Theft Deterrent System (Passlock) which is included on many 1996 and up GM vehicles.

Please note that this modification is intended to be used only in conjunction with the installation of a remote start/stop system and does not provide a procedure to install a remote start/stop system.

CAUSE If an attempt is made to start a vehicle by a means other than a key rotation in the ignition switch, the Body Control Module (BCM) will interpret this start as a vehicle theft and disable the fuel injectors.

CORRECTION A minor wiring modification may be made to allow the vehicle to be started remotely. This modification includes adding a switch to allow the customer to select ?ON? to allow remote starting or ?OFF? for normal Passlock operation.

CAUTION: When this modification is performed and the switch is set to the ON position, the theft deterrent feature will be disabled. When the theft deterrent is disabled the SECURITY/THEFT SYSTEM telltale will light up indicating that the theft deterrent system is NOT functioning.

PASSLOCK MODIFICATION Refer to appropriate GM service manuals and/or SVMQP Electrical Guideline Manual for instruction on splicing and electrical connections.

  1. Select a suitable on-off switch (see note below) which will be used to disable/ enable the Passlock System. Mount the switch in a location such that it is accessible to the driver and will not interfere with normal vehicle operation.

NOTE: This is an extremely low current circuit (approx. 7mA), it is therefore very important that a high quality, low energy, fast acting switch be utilized for this application.

  1. Turn the ignition switch to the OFF position.
  2. Locate the Main Ignition Switch Harness in the Column. GM's Passlock System wires exit the Ignition Switch Tumbler together and then join with the Main Ignition Switch Harness. (See
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    orhttp://64.85.6.118/diagrams/diagrams.asp and select your Make, Model andYear for wire colors and clues on the quickest way to access these wires.) 4. Locate the Yellow Passlock Data Wire which is included in a bundle ofthree tiny (20 GA) wires wrapped in friction tape.Cut this wire and splice a 0.5mm2 (20 GA) yellow wire to each end of the cutwire. Keep wire length to a minimum. Route modification wires clear of moving parts.

Connect the yellow wires to the switch such that the contacts are OPEN when the switch is in the ON position.

  1. Turn modification switch to the OFF postion (contacts closed).
  2. Start vehicle to verify normal operation. If engine ?cranks but will not start" recheck the switch position (contacts should be closed), wire connectors and modification wiring.

SWITCH OPERATION

To enable remote start: Start the engine with the ignition key (modification switch must be in the OFF position). Turn modification switch to the ON position (contacts open). The SECURITY/THEFT SYSTEM Telltale will light up indicating that the Passlock System is inoperative. Once the SECURITY/THEFT SYSTEM telltale has been on for at least 5 seconds the vehicle can be turned off and then remotely started.

To disable remote start: The Passlock System can be reactivated by turning the modification switch OFF (contacts closed). Vehicle can either be running or off when this is done.

Please note that the VCM/PCM will record Diagnostic Trouble Codes (DTCs) related to the security system when the modification switch is in the ON position (circuit open). This is due to the way that the VCM/PCM interprets this condition.

NOTICE Any condition which removes battery power from the Vehicle Control Module/Powertrain Control Module (VCM/PCM) (e.g. dead battery, disconnected harness connectors, etc.) will prevent the vehicle from being restarted. If the engine exhibits a ?cranks but will not start? symptom, place the modification switch in the OFF (contacts closed) position. This will reactivate the Passlock System and allow the vehicle to be started with the ignition key.

Ray

Proud Member of The Anti-Passlock Club

Reply to
Dog via CarKB.com
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I wish I could comment on this but I had better not...I'll just laugh to myself.

Reply to
dnoyeB
2002 Impala Sedan having had security problem since purchasing car-Thanks, I added a toggle switch to my plastic dash board to the left of the the key ignition. To to get at the yellow wire I had to remove the plastic dash board (1 piece), remove the metal plate under sterring colume, remove 2 bolt holding key ignition, pulled ignition key cylinder to the left and out after cutting harnesss support, splice the wires to prewired toggle and put all back together. I disconnected pos battery terminal prior to doing any of the work. With the passlock in disable mode (toggle switch off) the security light stays on while car running. This light bugs me and would like to know if anyone known how to stop light from coming on? The the only way it goes off now is when I enable the toggle switch to the on position when car is running and then I disable toggle switch to off position before shutting engine off.
Reply to
Tomb1957

If you followed the above way the answer is no. The BCM is seeing something wrong with the PK2 system and is ignoring it. The easier way is using a latching relay with the proper code instead of the rigging way of using a toggle switch. Man, thats gotta be ugly looking!

Reply to
ponchonutty

Well the system can't really be disabled. I'm surprised anyone would put in so much work to dance around a problem rather than just fixing the problem.

with your toggle switch off, if your car shuts off at highway speeds, can you restart it?

Reply to
dnoyeB

Yes!:wink: The car will restart. The previous no start (security) issue has been resolved by cutting the yellow wire exiting the ignition key cylinder and splicing a toggle switch to it. The steering wheel blocks the small toggle switch and I don?t find it \"ugly\". Anyway, you state and easier way such as \" latching relay with the proper code\" Please take the time and explain how this is to be done. I read of soldering a jumper wire with the correct resistor into the key recognition circuit to make the TDM \"think\" the key is always in the ignition but never read of any latching relay. So please take the time for the thousands of impala readers on how this security problem can be fixed with the latching relay. Thank you, Tomb1957:nono:

Reply to
Tomb1957

Sure. Visit this site to get familiar with these systems

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Once you understand the system, you can try this site and do what it states....
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I will warn you that you gotta have the system working in order to getthe proper code.

Reply to
ponchonutty

Thank You for the links on the passlock disablement.:nono:

Reply to
Tomb1957

Obviously, you have not owned a GM with a Passlock problem. These problems have been supposedly fixed properly time and time again by GM service techs. A year down the road, the problems start all over again. After $400 or $500 a pop, people are just desperate to not pour any more money into a parts replacement marathon. By the way, here are some links to the actual documents that the Disablement is taken from. I'm not prepared to argue with GM engineering.

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Ray

Reply to
Dog via CarKB.com

Yep, GM's way of fixing the problem is only temporary at best.

Reply to
ponchonutty

Its true. I never owned a high enough car for the system. I'm an engineer but I only worked on their 3rd version of the system. Its really totally different technology. Hopefully there are no such problems with it...

Reply to
dnoyeB

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