This information is in addition to the "Tires" portion located in Section 5 of your owner manual.
When tires are changed from the original equipment size to those adapted to railroad track gage, the Powertrain Control Module (PCM) must be reprogrammed to correct the speedometer reading.
Truck Models C/K 2500/3500: LY6 6.0L V8 Engine and MYD 6L90 Automatic Transmission.Reprogramming the PCM is done with a TECH II electronic diagnostic system. Your GM truck dealer has this equipment. Your dealer has the correct calibration identified by the calibration part numbers on the following chart and any later updates after this publication.
New Tire Size | Axle Code | Model Year | Calibration Part Number |
225/70R19.5 | GT4 (3.73) | 2007 | 12615865 |
225/70R19.5 | GT4 (3.73) | 2008 | 12615866 |
Please refer to the Light Duty Series GM BODY BUILDER BOOK or visit www.GMUPFITTER.com for further general information regarding vehicle modifications. | |||
