Gasoline Specifications (U.S. and Canada Only)
At a minimum, gasoline should meet ASTM specification D 4814 in the United States or CAN/CGSB-3.5 or 3.511 in Canada. Some gasolines contain an octane-enhancing additive called methylcyclopentadienyl manganese tricarbonyl (MMT). We recommend against the use of gasolines containing MMT. See Fuel Additives on page 9‑75 for additional information.
See also:
Canceling a Remote Start
To cancel a remote start:
• Aim the RKE transmitter at the vehicle and press and hold
until the parking lamps turn off.
• Turn on the hazard warning flashers.
• Turn the ignition on and t ...
XM™ Radio Messages
XL (Explicit Language Channels): These channels, or any others, can be blocked at a customer's request, by calling 1-800-929-2100 in the U.S. and 1-877-438-9677 in Canada.
XM Updating: The encryption ...
Customer Assistance Offices (U.S. and Canada)
GMC encourages customers to call the toll-free number for assistance.
However, if a customer wishes to write or e-mail GMC, the letter should be addressed to:
United States
GMC Customer Assistance ...





