PASSLOCK(tm) MODULE (THEFT DETERRENT CONTROL MODULE)

WARNING: This page is about a different car, the 2002 GMC Savana, 2002 Chevrolet Chevy Express, 2001 GMC Savana, and 2001 Chevrolet Chevy Express. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: Domestic models are equipped with Passlock(tm) module. Export and diesel models are equipped with a Vehicle Immobilizer Module (VIM). Passlock(tm) module may also be referred to as theft deterrent control module.

Passlock(tm) module contains the logic of theft deterrent system. Passlock(tm) module provides battery positive voltage to operate Passlock(tm) sensor. Passlock(tm) Module also measures voltage of security sensor signal circuit. Voltage measured will indicate whether Passlock(tm) sensor has been activated and whether resistance value from the sensor is a valid value or the tamper value. If voltage measured is in the valid range, Passlock(tm) module compares this voltage (voltage code) to a previously learned voltage code. If voltage codes match, Passlock(tm) module sends a class 2 message containing a password to PCM. If voltage codes do not match, or voltage is in tamper range, or there is a circuit fault, the Passlock(tm) module will not send the correct password to PCM, and vehicle will not start.