See also:

Range Selection Mode (Allison® Transmission or Hydra-Matic® 6-Speed Transmission)
The vehicle may have a Range Selection Mode. The Range Selection Mode helps control the vehicle's transmission and vehicle speed while driving down hill or towing a trailer by letting you select a d ...

Transmission
Electronic Range Select (ERS) Mode ERS mode allows you to choose the top-gear limit of the transmission and the vehicle's speed while driving downhill or towing a trailer. The vehicle has an electro ...

Engine Oil
For diesel engine vehicles, see “Engine Oil” in the Duramax Diesel Supplement. To ensure proper engine performance and long life, careful attention must be paid to engine oil. Following these si ...