GMC Cadillac CTS 2004 Owner's Manual page 196

Engine Coolant Hot – Idle Engine
This message will appear when the engine coolant
temperature is too hot. Stop and allow the vehicle to idle
until it cools down.
Notice: If you drive your vehicle while the engine is
overheating, severe engine damage may occur.
If an overheat warning appears on the instrument
panel cluster and/or DIC, stop the vehicle as soon as
possible. Do not increase the engine speed above
normal idling speed. See Engine Overheating
on page 5-31 for more information.
3-76
This symbol appears
with the Engine
Coolant Hot – Idle
Engine message.
Engine Coolant Hot – AC
(Air Conditioning) Off
This message displays when the engine coolant
becomes hotter than the normal operating temperature.
To avoid added strain on a hot engine, the air
conditioning compressor is automatically turned off.
When the coolant temperature returns to normal, the air
conditioning compressor will turn back on. You can
continue to drive your vehicle.
If this message continues to appear, have the system
repaired by your GM dealer as soon as possible to avoid
damage to the engine or transmission.
This symbol appears with
the Engine Hot – AC
Off message.