GMC Cadillac CTS 2004 Owner's Manual page 327

If No Steam Is Coming From
Your Engine
An overheat warning, along with a Check Coolant
Level message, can indicate a serious problem.
See DIC Warnings and Messages on page 3-70.
If you get an engine overheat warning with no Check
Coolant Level 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.
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 (N)
while stopped. If it is safe to do so, pull off the road,
shift to PARK (P) or NEUTRAL (N) and let the
engine idle.
2. Set the temperature control to the highest heat
setting and open the windows, as necessary.
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 and you have not stopped,
pull over, stop, and park your vehicle right away.
If there's still no sign of steam, you can idle the engine
for 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.
You may decide not to lift the hood but to get service
help right away.
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