Circuit Description
The coolant temperature sensor (CTS) is used by the electronic control module (ECM) to monitor
the temperature of the engine coolant. The coolant temperature is used by the ECM for the
engine protection system and the timing and fueling control.
Component Location
The coolant temperature sensor is located on top of the thermostat housing.
Shop Talk
Make sure the airflow through the radiator is not obstructed.
Cummins ISB CM550 (1990-94) Fault Code: 145 PID: 110 SPN: 110 FMI: 4 Engine Coolant Temperature 1 Sensor Circuit – Voltage Below Normal or Shorted to Low Source
Cummins ISB CM550 (1990-94) Fault Code: 145 PID: 110 SPN: 110 FMI: 3 Engine Coolant Temperature 1 Sensor Circuit – Voltage Below Normal or Shorted to Low Source
Cummins ISB CM550 (1990-94) Fault Code: 144 PID: 110 SPN: 110 FMI: 4 Coolant Temperature Sensor Circuit
Cummins ISB CM550 (1990-94) Fault Code: 144 PID: 110 SPN: 110 FMI: 3 Coolant Temperature Sensor Circuit
Cummins ISB CM550 (1990-94) Fault Code: 143-SW PID: 100 SPN: 100 FMI: 1 Oil Pressure Switch Circuit
Cummins ISB CM550 (1990-94) Fault Code: 143-SN PID: 100 SPN: 100 FMI: 1 Oil Pressure Switch Circuit
