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:
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
...
Brake System Messages
BRAKE FLUID LOW
This message is displayed when the brake fluid level is low; see Brake Fluid
on page 10‑24.
RELEASE PARKING BRAKE
This message is displayed as a reminder that the parking br ...
Ultrasonic Parking Assist
If available, the Ultrasonic Rear Parking Assist (URPA) system assists the driver with parking and avoiding objects while in R (Reverse). URPA operates at speeds less than 8 km/h (5 mph).
The sensors ...





