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 communicate with GMC by dialing:

1-800-462-8583. TTY users in Canada can dial 1-800-263-3830.

    See also:

    Automatic Dimming
    If equipped with an automatic dimming mirror, the driver outside mirror adjusts for the glare of the headlamps behind you. See Automatic Dimming Rearview Mirror on page 2‑17. ...

    Entering the Feature Settings Menu
    1. Turn the ignition on and place the vehicle in P (Park). To avoid excessive drain on the battery, it is recommended that the headlamps are turned off. 2. Press the customization button to enter th ...

    If the Off Indicator is Lit for an Adult-Size Occupant
    If a person of adult-size is sitting in the right front passenger seat, but the off indicator is lit, it could be because that person is not sitting properly in the seat. If this happens, use the ...