2101 John C. Watts Drive, Nicholasville, KY 40356
Fax 859.885.1731
800•654•0637
XXXXXXXXX
www.lockmasters.com
copyright © 2012 Lockmasters Inc. 5/12
Kobra Reader
™
Instructions for GM 10 Cut
2001 and up
KDGM10INST
2101 John C. Watts Drive, Nicholasville, KY 40356
800.654.0637
• Fax 859.885.1731
www.lockmasters.com
Copyright © 2008 Lockmasters Inc. 5/08
KDGM10INSTPDF
• Begin by cleaning the lock with CRC QD Electronic cleaner and exercising the tumblers with an uncut keyblank. The wafers
must move freely for you to get an accurate reading.
• Insert the reader fully into the lock with trap slot pointing up and the slide bar fully inserted into the reader.
• Withdraw the slide bar to the fully retracted position and slowly withdraw the reader until the wafer is trapped in the trap slot.
• Press in on the reader to bind the trapped wafer and then slowly move the slide bar toward the trap slot until it contacts
the wafer.
• Read the depth of this wafer and record the depth. Release the pressure on the reader and Insert the slide bar fully into
reader to release wafer, retract reader slightly, retract slide bar to open trap slot again, retract reader to trap next wafer.
• Repeat procedure to read all wafers located on the top side of the cylinder.
• Insert the reader fully into the lock with trap slot pointing down repeat the procedure above for all wafers located on the
bottom side of the cylinder.
• After you have read both sides of the lock, cut these depths in spaces 3-9 for a working door key. If the vehicle has a trunk or
deck lock then progress the 10th space in that lock.
• Complete the Ignition key by progressing the first & second space.
Tips for Kobra Reader
™
GM 10 Cut
1 Early GM 10 cut systems may have spaces 6-10 or 3-7 in the door lock. This will not help you in making a complete key as there are to
many progressions for the missing 5 cuts.
2 Some 97-up and most all 2001-up vehicles will contain spaces 3-9 in the door lock.
3 All EVEN spaces on one side and All ODD spaces on the other.
4 Wherever you trapped the deepest space in the lock
5 (top/bottom) that will be the Even spaces 10, 8 and 6, the other side will have Odd spaces 9 and 7 on early systems.
6 Deepest space trapped on the 2001-up will be the #9 space and that will be the Odd Side 9, 7, 5 and 3 with 8, 6 and 4 on the other side.
7 The depth marks on the reader will indicate a 4 depth closest to the bow of the reader and the 1 depth closest to the tip of the reader.
8 Always start from the rear of the lock (deepest space) and read the wafers out to the front (facecap).
9 Make a tumbler chart and fill in the depths as you read the lock.
10 Remember to cut your key correctly with the cuts in the 3-9 spaces for 2001-up or vehicles using 3-9 in the door lock.
11 Progress the 10 cut in the trunk and progress the 1,2 spaces in the ignition. You may use a “fill” program to “find the missing cuts or
just progress using this chart.
1st Key
11, 12
13, 23
24, 34
2nd Key
21, 22
32, 33
3rd Key
31
