Engine Coolant Heater
The engine heater can provide easier starting and better fuel economy during engine warm-up in cold weather conditions at or below −18°C (0°F). Vehicles with an engine heater should be plugged in at least four hours before starting.
An internal thermostat in the plug-end of the cord may exist which will prevent engine coolant heater operation at temperatures above −18°C (0°F).
If the vehicle has a diesel engine, see the Duramax Diesel supplement for more information.
See also:
Compass Variance (Zone) Procedure
1. Do not set the compass zone when the vehicle is moving.
Only set it when the vehicle is in P (Park).
Press the vehicle information button until PRESS TO CHANGE COMPASS ZONE displays.
2. Find ...
After Off-Road Driving
Remove any brush or debris that has collected on the underbody or chassis, or
under the hood. These accumulations can be a fire hazard. After operation in mud
or sand, have the brake linings clean ...
Headlamp Aiming
The vehicle has a visual optical headlamp aiming system. The aim of the headlamps has been preset at the factory and should need no further adjustment.
However, if the vehicle is damaged in a crash, ...





