Key and Lock Cylinder Coding. GMC Truck TopKick C-Series (Crew) C4/C5 2005

For 1990-2009 cars only

Makes 🢒 GMC_Truck 🢒 2005 🢒 TopKick C-Series (Crew) C4/C5 🢒 General Information 🢒 General Information 🢒 Key and Lock Cylinder Coding

Medium Duty Trucks use a one-key locking system. A single, two-sided key operates the ignition and both doors. The key is reversible, and inserts with either side facing up.

Identify keys by the 5-character key code stamped onto the key. Use the code numbers and a code list in order to determine the lock combination of the vehicle. The owners of key cutting equipment receive the code list from equipment suppliers. If the code number is not available from records or from the five-character key code number, a key code number label is on the inside of the bottom glass on the passenger's side door.

Key Code Diagram


(1)	Position
(2)	Level

Cutting Keys

Determine the code from the code list or the key code diagram.
Cut a blank key to the proper level for each of the eight tumbler positions.
Ensure that the key locks and unlocks the lock cylinder.

Replacement Lock Cylinders

The service parts warehouses offer lock cylinders as a complete assembly, including the key. Do not service or code the lock cylinders. If a lock cylinder is faulty, replace the cylinder. Order lock cylinders from the service parts warehouses.