Engine Coolant Hot Idle Engine

WARNING: This page is about a different car, the 2003 Oldsmobile Bravada, 2003 GMC Envoy XL, 2003 GMC Envoy, and 2003 Chevrolet TrailBlazer. However, it is still accessible from the selected car via links, so may be relevant.

The radio activates an audible warning as requested by the instrument panel cluster (IPC). The IPC sends a class 2 message to the radio indicating the chime duration of 4 pulses. The warning sounds and the appropriate indicator illuminates in the driver information center (DIC) when the following occurs:

The IPC determines that the coolant temperature is greater than 125°C (257°F). The IPC receives a class 2 message from the PCM indicating coolant temperature.
The IPC performs the displays test at the start of each ignition cycle. The indicator illuminates for approximately 3 seconds.

The IPC turns OFF the engine coolant indicator when the engine coolant falls below 122°C (252°F).