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
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.
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.
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.
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
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
for this application.
2. Turn the ignition switch to the OFF position.
3. 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 http://www.bulldogsecurity.com/ or
http://126.96.36.199/diagrams/diagrams.asp and select your Make, Model and
Year 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 of
three 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 cut
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.
5. Turn modification switch to the OFF postion (contacts closed).
6. Start vehicle to verify normal operation. If engine “cranks but will not
recheck the switch position (contacts should be closed), wire connectors and
To enable remote start:
Start the engine with the ignition key (modification switch must be in the
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
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
Proud Member of The Anti-Passlock Club
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