Chevrolet 2004 Impala, Owner'S Manual, Page: 90 / 410

Engine Coolant Heater
Your vehicle may be equipped with this feature. In very
cold weather, 0°F (
−
18°C) or colder, the engine
coolant heater can help. You’ll get easier starting and
better fuel economy during engine warm-up. Usually, the
coolant heater should be plugged in a minimum of
four hours prior to starting your vehicle. At temperatures
above 32°F (0°C), use of the coolant heater is not
required.
To Use the Engine Coolant Heater
1. Turn off the engine.
2. Open the hood and unwrap the electrical cord.
The cord is attached to the underside of the
diagonal brace, which is located above the engine
air cleaner/filter assembly.
3. Plug it into a normal, grounded 110-volt AC outlet.
{
CAUTION:
Plugging the cord into an ungrounded outlet
could cause an electrical shock. Also, the
wrong kind of extension cord could overheat
and cause a fire. You could be seriously
injured. Plug the cord into a properly grounded
three-prong 110-volt AC outlet. If the cord will
not reach, use a heavy-duty three-prong
extension cord rated for at least 15 amps.
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