Cummins ISB CM550 (1990-94) Fault Code: 151 PID: SPN: FMI: Coolant Temperature – Engine Protection

Circuit Description
The coolant temperature sensor 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, timing, and fueling control.

Component Location
The coolant temperature sensor is located on the engine in the thermostat housing area.

Shop Talk
Make sure the airflow through the radiator is not obstructed.