New Holland ENG 293 – Engine Control Module (ECM) / Engine Controller: Hydraulic Fan Hydraulic Oil Temperature Sensor Voltage is too high

The control module is receiving a voltage signal from the hydraulic oil temperature sensor that exceeds the maximum expected threshold, indicating an open circuit, short to power (+V), or internal sensor failure.

• T-series tractors
• CR/CX combines
• forage harvesters

1. 1

   Visually inspect the hydraulic oil temperature sensor electrical connector for disconnected plugs, backed-out pins, moisture, or corrosion.

2. 2

   Inspect the wiring harness from the sensor to the Engine Controller for chafed wires shorting to power or severed wires causing an open circuit.

3. 3

   Disconnect the sensor, turn the key ON, and use a multimeter to verify the ECM is supplying a 5V reference voltage and a solid ground.

4. 4

   Measure the resistance across the sensor's terminals. If the multimeter reads 'OL' (Open Loop), the sensor has failed internally and must be replaced.

1. 1

   Safety First

   Park the machine on a level surface, lower all implements, turn off the engine, and disconnect the negative battery cable.

2. 2

   Locate the Sensor

   Find the hydraulic fan hydraulic oil temperature sensor on the hydraulic pump/fan circuit.

3. 3

   Disconnect

   Unplug the electrical connector from the sensor.

4. 4

   Prepare for Fluid Loss

   Place a clean catch pan directly beneath the sensor area, as removing the sensor will release hydraulic fluid.

5. 5

   Remove the Sensor

   Use a wrench or deep socket to carefully unscrew the faulty sensor from the hydraulic port.

6. 6

   Install the New Part

   Thread the new hydraulic oil temperature sensor into the port. Tighten it to the manufacturer's specified torque (do not over-tighten, as this can damage the brass threads or the housing).

7. 7

   Reconnect

   Plug the electrical connector back into the new sensor, ensuring it clicks and locks into place.

8. 8

   Refill and Test

   Reconnect the battery. Check the hydraulic oil level and top off any fluid lost during the swap. Start the machine, clear the inactive ENG 293 fault code using a diagnostic scan tool, and run the equipment to operating temperature to ensure the code does not return and there are no leaks.