Case IH 3460 (F-175-18) - ECU – Engine Control Unit (ECU) / Engine Control Module (ECM): Engine oil temperature too low

This code triggers when the control system detects that the engine oil temperature is operating below the minimum expected threshold for the current engine load and run time. This is most commonly caused by a failed temperature sensor (reading an open circuit or skewed resistance), a wiring issue, or an engine that is genuinely failing to reach operating temperature due to a stuck-open coolant thermostat.

• VESTRUM CVX
• Maxxum series (110–150)
• Puma series (115–240)
• Magnum series (e.g., 235)
• Steiger 4WD tractors (380–485)
• Combines 5140–9240 series
• Combines 7010–9120 series
• AFX8010
• Patriot 3230
• Patriot 3330
• Titan Floaters
• 580/590 series Backhoe Loaders (SM, SN)
• Wheel Loaders (521F through 1121G)

1. 1

   Visual Wiring & Connector Inspection: Locate the combined oil temperature/pressure sensor on the engine block. Unplug the 4-pin weather-sealed connector and inspect it for oil, which indicates a ruptured internal diaphragm.

2. 2

   Harness Check: Inspect the wiring harness leading back to the ECU for chafing, corrosion, or a short-to-ground.

3. 3

   Thermostat Verification: Verify if the engine is actually warming up. A stuck-open coolant thermostat will prevent the oil from reaching operating temperature.

4. 4

   Sensor Resistance Test: Use a multimeter to test the resistance across the temperature pins on the sensor. Infinite resistance indicates a failed internal thermistor.

1. 1

   Preparation

   Park the machine on a level surface, turn off the engine, and remove the key. Allow the engine to cool to avoid burns from hot oil or exhaust components.

2. 2

   Locate the Sensor

   Find the combined engine oil temperature and pressure sensor. It is threaded directly into the main engine oil gallery line on the engine block.

3. 3

   Disconnect

   Carefully release the locking tab and unplug the 4-pin electrical connector from the sensor.

4. 4

   Removal

   Place a small catch pan underneath the sensor area, as a small amount of engine oil will drain out when the sensor is removed. Use a wrench to unscrew the brass sensor from the block.

5. 5

   Installation

   Thread the new sensor into the port. The OEM sensor utilizes an M10 standard taper pitch thread. Tighten it securely, but do not overtighten, as the brass base can shear.

6. 6

   Reconnect

   Clean the wiring harness plug with electrical contact cleaner (especially if oil pushed into it from the old sensor) and plug it into the new sensor until it clicks.

7. 7

   Finalize

   Check the engine oil dipstick and top off any oil lost during the swap. Turn the key on, clear the ECU fault codes via the in-cab display or a diagnostic tool, and start the engine to verify that the code does not return and the temperature registers correctly.