PIN 3735700 - Caterpillar

Table 1
High Coolant Temperature    
Parameter     Default Setting    
Warning setpoint    
102 °C (216 °F)    
Warning delay     5 seconds    
Derate setpoint    
107 °C (225 °F)    
Derate delay     30 seconds    
Maximum time of derating     480 seconds    
Hysteresis    
5 °C (9 °F)    
Security level     No required password    
Maximum derating     25%    
Shutdown setpoint    
107 °C (225 °F)    
Shutdown delay     5 seconds    If the coolant temperature is above 102 °C (216 °F) for five seconds, a warning will occur. The coolant temperature must be below 97 °C (207 °F) in order to deactivate the warning.If the coolant temperature is above 107 °C (225 °F) for 30 seconds, a derating will occur. A continuous 25 percent derating is reached in 480 seconds. When the coolant temperature is less than 102 °C (216 °F), the percent of the derating decreases. The percent of the derating decreases until the capability of providing full power is restored. However, if the coolant temperature rises above the setpoint again, the derating will resume.If the coolant temperature is above 107 °C (225 °F) for five seconds, a shutdown will occur.Note: The default setting for the delay of the derating is programmed to the maximum value of 30 seconds. The delay for the shutdown is five seconds. These settings result in a shutdown that occurs before a derating. These settings are programmed because most customers prefer a shutdown for high coolant temperature. The settings can be programmed to different values.The setpoint can be programmed in the range of 90 to 102 °C (194 to 215 °F).Coolant Temperature Input Circuit
The temperature of the engine coolant is measured by an electronic sensor. The sensor is mounted on the cover of the regulator housing. The signal from the sensor is used to modify the fueling of the engine. The signal is also used to modify the timing for an improved cold start and reduction in white smoke. The ECM supplies the coolant temperature sensor with 5.0 0.5 VDC. The sensor's output voltage is 0.4 to 4.6 VDC. This depends on the temperature of the engine's coolant.