See also:

Customer Assistance for Text Telephone (TTY) Users (U.S. and Canada)
To assist customers who are deaf, hard of hearing, or speech impaired and who use Text Telephones (TTYs), GMC has TTY equipment available at its Customer Assistance Center. Any TTY user can communicat ...

Heavy-DutyTrailer Wiring Harness Package
For vehicles equipped with heavy duty trailering, the harness connector is mounted in the bumper. The seven-wire harness contains the following trailer circuits: • Yellow: Left Stop/Turn Signal ...

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 ...