Conditions
Important: If a new vehicle control module (VCM) is being installed for the first
the manufacturing enable bit will be set and the auto learn procedure may
not be necessary.
The following procedure allows for anyone to reprogram the passlock™/EVO
module learned data code with any tools, other than the scan tool, when any
of the following parts are replaced:
• | The passlock™/EVO module |
The passlock™/EVO module will set the DTC B3031 module
in the learn mode when entering the reprogramming procedure.
Steps
Important: Erase the passlock™ related diagnostic trouble codes (DTCs) that
are stored in the VCM. If there are any powertrain related DTCs, record these
DTCs and refer to
Powertrain On Board Diagnostic (OBD) System Check
in Engine Controls - 4.3L
In addition to the time involved in performing the specific steps, the
Seed and Key procedure accomplishes the same task in 10 minutes as
the Auto Learn procedure does in 30 minutes. To perform the Seed and
Key Learn procedure, refer to
PASSLOCK Reprogramming Seed and Key
.
The following is the Auto Learn Procedure:
- Insure the ignition key is in the ON position.
- Clear all passlock™/EVO module and VCM DTCs. Record and
refer any VCM DTCs to
Powertrain On Board Diagnostic (OBD) System Check
in Engine Controls - 4.3L
- Momentarily rotate the ignition key to the CRANK position (Do
NOT start the vehicle), then release it to the RUN position (Do NOT key OFF
in the process).
- Wait 10 minutes. Observe the SECURITY indicator. Refer to the
following list for the appropriate responses:
• | If the passlock™ sensor was replaced the SECURITY indicator
will flash for the 10 minutes duration. |
• | If the passlock™/EVO module was replaced, the SECURITY indicator
will flash for a few seconds and then remain ON for the remainder of the 10 minutes
duration. |
• | If the VCM was replaced with a new programmed VCM and connected
to the vehicle for the first time, the vehicle will start and this procedure
may not be necessary. |
• | If the replacement VCM was connected to any vehicle at any other
time, even momentarily, the SECURITY indicator will flash for a few seconds
and then remain ON for the 10 minutes duration. |
- The SECURITY indicator will transition from flashing to ON briefly
to OFF after 10 minutes if remaining in the ignition ON position.
- Turn the ignition switch to the OFF position and wait for 10 seconds.
- Repeat steps 3-6 two more times. The new security code is
ready to be communicated among the Passlock sensor, Passlock/EVO module and
VCM. The new password is learned on the next ignition lock cylinder cycle
from OFF to CRANK to ON (start attempt).