C 3500 HD Truck 2WD V8-8.1L VIN G (2002)
Lock Cylinder Switch: Description and Operation
PASSLOCK(TM) SENSOR
The Passlock(TM) sensor is inside the lock cylinder housing. The Passlock(TM) sensor contains 2 hall effect sensors. The tamper hall effect sensor is on
the top. The security hall effect sensor is under the tamper hall effect sensor. Both of the hall effect sensors monitor the magnet of the lock cylinder
through an opening. The tamper hall effect sensor is physically placed on top of the security hall effect sensor. This arrangement enables the tamper hall
effect sensor to engage first if an intruder attempts to bypass the Passlock(TM) sensor by placing a large magnet around that area of the steering column.
There is a tamper resistor inside the Passlock(TM) sensor in order to help prevent tamper to the system. Passlock(TM) equipped vehicles have a
selection of 10 different security resistors ranging from 0.5 K ohms up to 13.6 K ohms. Installing one of the security resistors inside the Passlock(TM)
sensor will generate a unique Passlock(TM) code. All 10 combinations of the Passlock(TM) sensor have the same part number. However, you cannot
simply replace the Passlock(TM) sensor and expect the system to operate properly. Always start by performing the Diagnostic System Check first and
following the instructions.
