HOLDER-TOOTH 2726089 - Caterpillar

System Operation Description:Use this procedure to troubleshoot any suspect problems with the following sensors:
Coolant temperature sensor
Inlet manifold temperature sensor
Fuel temperature sensorThis procedure covers the following diagnostic codes:
110-03 Engine Coolant Temperature open/short to +batt
110-04 Engine Coolant Temperature short to ground
172-03 Intake Manifold Air Temp open/short to +batt
172-04 Intake Manifold Air Temp short to ground
174-03 Fuel Temperature open/short to +batt
174-04 Fuel Temperature short to groundThe troubleshooting procedures for the diagnostic codes of each temperature sensor are identical. The temperature sensors are passive sensors that have two terminals. The temperature sensors do not require supply voltage from the Electronic Control Module (ECM).Pull-up VoltageThe ECM continuously outputs a pull-up voltage on the circuit for the sensor signal wire. The ECM uses this pull-up voltage in order to detect an open in the signal circuit. When the ECM detects the presence of a voltage that is above a threshold on the signal wire, the ECM will generate a -03 diagnostic code.If the sensor is disconnected at the sensor connector, the presence of pull-up voltage at the sensor connector indicates that the signal wire and the return wire