GMC 2004 Sierra - Manual (Page 438)

If No Steam Is Coming From Your
Engine
An overheat warning, along with a low coolant condition,
can indicate a serious problem. For more information,
see
Driver Information Center (DIC) on page 3-55.
If you get an engine overheat warning and don’t have a
low coolant condition, but see or hear no steam, the
problem may not be too serious. Sometimes the engine
can get a little too hot when you:
• Climb a long hill on a hot day.
• Stop after high speed driving.
• Idle for long periods in traffic.
• Tow a trailer. See “Driving on Grades” under
Towing a Trailer on page 4-70.
If you get the overheat warning with no sign of steam,
try this for a minute or so:
1. If you have an air conditioner and it’s on, turn it off.
2. Turn on your heater to full hot at the highest fan
speed and open the window as necessary.
3. If you’re in a traffic jam, shift to NEUTRAL (N);
otherwise, shift to the highest gear while
driving – AUTOMATIC OVERDRIVE
X
or
DRIVE (D) for automatic transmissions.
If you no longer have the overheat warning, you can
drive. Just to be safe, drive slower for about 10 minutes.
If the warning doesn’t come back on, you can drive
normally.
If the warning continues, pull over, stop, and park your
vehicle right away.
If there’s still no sign of steam, push down the
accelerator until the engine speed is about twice as fast
as normal idle speed for at least three minutes while
you’re parked. If you still have the warning,
turn off the
engine and get everyone out of the vehicle until it
cools down. Also, see “Overheated Engine Protection
Operating Mode” listed previously in this section.
You may decide not to lift the hood but to get service
help right away.
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