New Holland 3813 – Engine ECU: ECU Temperature Sensor Range Low

The engine's Electronic Control Unit (ECU), also known as the Electronic Diesel Control (EDC), has detected an abnormally low temperature reading from its own internal temperature sensor. This indicates that the measured temperature is outside the expected operational range, pointing to a potential internal hardware fault within the ECU itself rather than an issue with an external engine sensor.

• T6
• T7
• T8
• CX
• CR
• CR9.90
• W130B
• W170B
• W190B
• L160
• L170
• L175
• E215B
• TM

1. 1

   Visually inspect the wiring harness and connectors associated with the engine control unit for damage, corrosion, or loose connections that could cause a short circuit

2. 2

   Check for other active fault codes related to sensor supply voltage or other engine sensors to gather additional diagnostic clues

3. 3

   With the ignition off, disconnect the lead from the coolant temperature sensor. Turn the key on and measure voltage between the lead terminal and chassis; a deviation from battery voltage indicates a wiring, fuse, or gauge issue

4. 4

   With the key off, measure resistance between the sensor terminal and chassis using an ohmmeter. An open circuit (infinite resistance) or dead short (zero resistance) indicates a faulty sensor. Compare the resistance reading to the expected values at a given temperature, if available in the service manual.

1. 1

   Locate the sensor

   Find the engine coolant temperature sensor, typically located on the engine head near the thermostat housing or on the water outlet sump (on FPT engines, it may be on the thermostat housing or cylinder head water jacket tract).

2. 2

   Drain coolant

   Partially drain the engine coolant to a level below the sensor to prevent spillage during removal.

3. 3

   Remove the old sensor

   Disconnect the electrical connector and carefully remove the old sensor using an appropriate wrench or sensor socket.

4. 4

   Install the new sensor

   Apply a suitable thread sealant or anti-seize compound to the threads of the new sensor (avoiding the sensing element). Install and tighten to the manufacturer's specified torque.

5. 5

   Reconnect and refill

   Reconnect the electrical connector and refill the cooling system with the appropriate coolant.

6. 6

   Clear Fault Codes

   Use a diagnostic tool to clear the fault code 3813 and any other related codes.

7. 7

   Verify the Repair

   Start the engine and let it run to operating temperature, monitoring the temperature gauge and checking for any leaks. Re-scan for fault codes to ensure the issue is resolved.