BREATHER AS 9Y2988 - Caterpillar

The ECM will automatically warn the operator of low coolant temperature. The default settings that are programmed at the factory are listed in Table 1.
Table 1
Low Coolant Temperature
Parameter Default Setting
Warning setpoint 80 °C (176 °F)
Warning delay 5 seconds
Activation delay 10 minutes
Hysteresis 0 °C (0 °F)
Security level No required password To activate this strategy, the engine must operate for a minimum of ten minutes at an average load of 20 percent or more. If the average load is 20 percent or more and the coolant temperature is below 80 °C (176 °F) for five seconds, a warning will occur. To deactivate the warning, one of the following conditions must occur:
The average load for ten minutes must decrease to less than 20 percent.
The coolant temperature must rise above 80 °C (176 °F).The setpoint can be programmed in the range of 63 to 85 °C (145 to 185 °F).Note: The low coolant temperature is monitored in order to detect a failure of the water temperature regulators. This feature is not intended to monitor the operation of jacket water heaters.