Chevrolet 2003 Tahoe Owner's Manual page 385

If No Steam Is Coming From
Your Engine
An overheat warning, along with a low coolant message,
can indicate a serious problem. See Low Coolant
under DlC Warnings and Messages on page 3-62.
If you get an engine overheat warning with
no
low
coolant message, 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 Towing a Trailer on page 4-59.
If you get the overheat warning with no sign of steam, try
this for a minute or so:
1. In heavy traffic, let the engine idle in neutral while
stopped. If it is safe to do so, pull off the road. Shift
to park or neutral and let the engine idle.
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, you can 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 sewice
help right away.
2. Turn on your heater to full hot at the highest fan
speed and open the window as necessary.
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