This applies only to vehicles that feature Option Package EMP (Enhanced Mobility Package).
When tires are changed from the original equipment size to those adapted to off-road usage, the Engine Control Module (ECM) must be reprogrammed to correct the speedometer reading.
This reprogramming will also limit maximum vehicle speed to 93 mph (150 km/h).
Truck models K 2500: LLY/LB7 6.6 L V8 Diesel Engine and M74 Automatic Transmission.
Reprogramming the ECM is done with a TECH II electronic diagnostic system. Your GM Goodwrench® 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.
Model Year | Engine | Transmission | New Tire Sizes | *Calibration P/N |
|---|---|---|---|---|
2003/2004 | LB7 | M74 | LT285/75R16 (628 Rev/Mile) (392 Rev per Kilometer) | 15130245 |
2004 | LLY | M74 | LT285/75R16 (628 Rev/Mile) (392 Rev per Kilometer) | 15130246 |
2005 | LLY | M74 | LT285/75R16 (628 Rev/Mile) (392 Rev per Kilometer) | 15130247 |
Please refer to the light duty series GM BODY BUILDER BOOK for further general information regarding vehicle modification. | ||||
* New calibrations include maximum vehicle speed of 93 mph (150 km/h) | ||||
