Circuit/System Description

The instrument panel cluster (IPC) illuminates the engine coolant temperature indicator when the engine control module (ECM) determines that the coolant temperature is more than 128°C (262°F). The IPC receives a serial data message from the BCM requesting the illumination of the engine coolant temperature indicator. The IPC turns the engine coolant temperature indicator ON and OFF during the display test to verify the indicator is working properly at the start of each ignition cycle.