Express 3/4 Ton Van V8-305 5.0L VIN M SFI (1999)
Alarm Module: Service and Repair
Passlock Reprogramming Seed and Key Disclaimer
DISCLAIMER
This step by step procedure is intended to augment the Passlock TM Diagnostic Repair Procedures. Sole reliance on this procedure may lead to
unintended results.
EQUIPMENT
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CD-ROM database containing the passlock seed and key algorithm loaded on a computer with class 2 capability
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Scan Tool TECH 2 or a compatible scan tool
CONDITIONS
IMPORTANT: If a new vehicle/powertrain control module (VCM/PCM) is being installed for the first time the manufacturing enable bit will be
set and the auto learn procedure may not be necessary. The following procedure allows the relearning of the Passlock TM module or the
VCM/PCM learned data code after the replacement of any of the following parts:
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The Passlock TM module
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The passlock TM sensor
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The VCM/PCM
The Passlock TM module will set the DTC B3031 module in the learn mode when entering the reprogramming procedure.
STEPS
IMPORTANT: Erase the passlock TM related Diagnostic Trouble Codes (DTCs) that are stored in the VCM/PCM. Record, then refer these
DTCs to:
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For 4.3L engines, refer to A Powertrain On Board Diagnostic (OBD) System Check in Engine Controls - 4.3L
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For 5.0/5.7L engines, refer to A Powertrain On Board Diagnostic (OBD) System Check in Engine Controls - 5.0/5.7L
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For 6.5L engines, refer to A Powertrain On Board Diagnostic (OBD) System Check in Engine Controls - 6.5L
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For 7.4L engines, refer to A Powertrain On Board Diagnostic (OBD) System Check in Engine Controls - 7.4L
IMPORTANT: 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. Use either one of these two procedures.
The following is the Seed and Key Learn Procedure:
1. Insure the ignition key is in the ON position.
2. Insure all passlock TM module and VCM/PCM DTCs have been cleared.
3. With scan tool (TECH 2) connected to the vehicle, select "Programming/Request Info" from menu, then follow instructions.
4. Disconnect scan tool from vehicle and perform "Service Programming System/VTD Learn" with Techline terminal, then follow instructions.
5. Reconnect scan tool to the vehicle.
6. Follow instructions on the scan tool to perform the VTD password learn on the vehicle, this takes about 10 minutes.
7. After 10 minutes, the SECURITY indicator will turn OFF. The new security code is ready to be communicated among the Passlock sensor,
Passlock module and VCM/PCM. The new Password is learned on the next ignition lock cylinder cycle from OFF-to-CRANK-to-ON (start
attempt).
