Reduced Engine Power
WARNING: This page is about a different car, the 2007 Hummer H2. However, it is still accessible from the selected car via links, so may be relevant.
The IPC illuminates the REDUCED ENGINE POWER indicator in the message center when the IPC detects a reduced engine power condition from the PCM. The IPC receives a class 2 message from the PCM requesting illumination when the engine temperature reaches 128°C (262°F).