2010 Cadillac STS Owner's Manual - Page 260

ENGINE COOLANT HOT IDLE ENGINE 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 6‑32 for more information. This symbol appears with this message. ENGINE HOT - AC (Air Conditioning) OFF This message displays when the engine coolant becomes hotter than the normal operating temperature. See Engine Coolant Temperature Gage on page 4‑61. 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 turns back on. You can continue to drive your vehicle. If this message continues to appear, have the system repaired by your dealer/retailer as soon as possible to avoid damage to the engine. ENGINE POWER REDUCED This message displays when the engine coolant temperature is too hot. Stop and allow the vehicle to idle until it cools down. See Engine Coolant Temperature Warning Light on page 4‑61. See Overheated Engine Protection Operating Mode on page 6‑34 for information on driving to a safe place in an emergency. This message displays when the engine power is being reduced to protect the engine from damage. There could be several malfunctions that might cause this message. Reduced engine power can affect the vehicle's ability to accelerate. If this message is on, but there is no reduction in performance, proceed to your 4-80