LEMON Manuals: Even more car manuals for everyone
Home >> GMC >> 2000 >> Yukon Denali >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 1 (Anti-Theft System) >> Operation >> PASSLOCK(tm) SYSTEM

PASSLOCK(tm) SYSTEM

WARNING: This page is about a different variant/trim than selected.

When mechanical key turns Passlock(tm) 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 the Passlock(tm) module. The module determines validity of R-Code within a preset time window, then sends a coded password to Powertrain Control Module (PCM) or Vehicle Control Module (VCM), which then allows fuel injectors to operate normally.

If Passlock(tm) module receives the incorrect R-Code, PCM/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, PCM/VCM will enter lock-out mode. If a large magnet is placed near Passlock(tm) sensor or a tamper (wrong key) exists, PCM/VCM will enter lock-out mode. Lack of data from Passlock(tm) sensor to Passlock(tm) module will set Diagnostic Trouble Codes (DTC) and illuminate SECURITY indicator light.