Cadillac 2004 CTS - Manual (Page 193)

Service AC (Air Conditioning) System
This symbol appears with
the Service AC System
message.
This message appears when the electronic sensors that
control the air conditioning and heating systems are
no longer working. Have the climate control system
serviced if you notice a drop in heating and air
conditioning efficiency.
Service Air Bag
This symbol appears with
the Service Air Bag
message.
There is a problem with the air bag system when this
message appears. Have your vehicle serviced by
a qualified technician at your dealership immediately.
See
Air Bag Readiness Light on page 3-38 for more
information.
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