PASSLOCK™ System

WARNING: This page does not describe the selected car, but rather 15 other vehicles, including the 2000 GMC Yukon, 2000 GMC Savana Special, 2000 GMC Savana Camper Special, 2000 GMC Savana, and 2000 GMC Pickup. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: Passlock™ module may also be referred to as EVO/Passlock™ module.

When mechanical key turns Passlock™ lock cylinder, a Resistance Code (R-Code) is created by a rotating magnet turning past a stationary Hall Effect sensor. R-Code is sent to Passlock™ module. The module determines validity of R-Code within a preset time window, then sends a coded password to Vehicle Control Module (VCM), which then allows fuel injectors to operate normally.

If Passlock™ module receives an incorrect R-Code, VCM will enter long tamper mode. During long tamper mode, fuel injectors are shut off for 10 minutes and SECURITY indicator light will flash. Vehicle may crank and temporarily start during long tamper mode, but will soon stall due to fuel shut-off. If coded password is not received or is incorrect by the time engine starts, VCM will enter lock-out mode. If a large magnet is placed near Passlock™ sensor or a tamper (wrong key) exists, VCM will enter lock-out mode. Lack of data from Passlock™ sensor to Passlock™ module will set DTCs and illuminate SECURITY indicator light.