Malibu V6-191 3.1L VIN M SFI (1997)
Coolant Level Indicator Lamp: Description and Operation
The Low Coolant indicator (amber) will be illuminated to indicate to the driver that the Engine Coolant level is low. The Engine Coolant Level Switch is
a discrete input to the Body Function Controller (BFC) which will close when the Engine Coolant is low. The indicator will illuminate when the input
has been active low for at least 10 seconds and the Ignition Switch is in the RUN position. The indicator will be commanded OFF if the switch input
goes inactive for at least 2 seconds. This is a distributed function between the Body Function Controller (BFC) and the Instrument Cluster. The Body
Function Controller (BFC) will read the status of the Engine Coolant Level Switch input and determine indicator control and then send the control state
to the
Instrument Cluster via the Serial Peripheral Interface (SPI) serial data bus. The Instrument Cluster will read the Low Coolant indicator control state in
the Serial Peripheral Interface (SPI) message and control the indicator directly. In the event of an Serial Peripheral Interface (SPI) data link failure, the
Low Coolant indicator will not illuminate unless the indicator was illuminated prior to the Serial Peripheral Interface (SPI) data link failure.
