See also:

Unable to Connect to OnStar Message
If there is limited cellular coverage or the cellular network has reached maximum capacity, this message may come on. Push Q to try the call again or try again after driving a few miles into anoth ...

Footnotes — Maintenance Schedule Additional Required Services — Severe
a) Extreme service. For vehicles mainly driven off-road in four-wheel drive or used in farming, mining, forestry, Department of Natural Resources (DNR), or snow plowing. b) Check all fuel and vapor l ...

Tires
Use a stiff brush with tire cleaner to clean the tires. Notice: Using petroleum-based tire dressing products on the vehicle may damage the paint finish and/or tires. When applying a tire dressing, ...