This is something I cut-and-pasted onto my hard drive off of TDS a while back, but it's what I used when I took my truck to the dealer for a speedometer re-cal and it worked just fine:
Special Service Message 11789 & 11790 from 7/29/99 (updated to include 2002 PSDs).
1)Ensure all harness connections are plugged in.
2)Using Rotunda New Generation Star (NGS) scanner and Version 3.2 or higher Service Card, Plug into the DCL connector. [ADDED: Do not use a service card version later than early 2001 model year. This will not work if you try to use a service card dated after the 2002 models came out. But it will work on 2002 or earlier trucks if you use a Service Card for 2001 or earlier SuperDuties.]
3)Turn Key on w/Engine Off.
4)Select Service Bay Functions
5)Select ABS Module or 4WABS Module depending on application. (All 2002 SuperDuties have 4WABS - 4-wheel ABS)
6)Select Tire Size/Axle Ratio Configure.
7)Enter tire manufacturer's specification of revs/mile (tire revolutions per mile). If not available, use Formula of: 63360 Divided by the Circumfrence of the tire measured in inches. Add 2 zeros in front of the solution. Enter this number into the NGS as the REV.PER MILE figure. [ADDED: To be even more accurate, enter the following rev/mile:
For 285/75R16 tires enter 00636 (except Dunlop)
For 295/75R16 tires enter 00626
For 315/75R16 tires enter 00601
Do not try to enter a number less than 00601.]
8)Select Tone Ring size and verify that 120 is programmed in.
9)Select <Option> and press TRIGGER.
10)Select <Vehicle> and press TRIGGER.
11)Press <Done> and the Module will be reprogrammed.
12)Check Speedo accuracy.
Bill
