Express 1/2 Ton Van V6-4.3L VIN W (1999)
Ignition Lock: Description and Operation
The mechanical block is a cable mounted finger added to the lock module. The cable passes through the lock module only when the shift lever is in the
P or N position. This prevents turning the ignition lock cylinder to the START position when the transmission is in DRIVE.
When the shift lever is in either the P or N position, the cable passes through the lock module notches, allowing the lock cylinder to turn to the
OFF-LOCK Position.