Case IH 3965 (DTC 245D) - ECU – Engine Control Unit (ECU / EDC): ECU temperature sensor 2 is too low

The secondary temperature sensor monitoring the Engine Control Unit (ECU) has registered a temperature value that falls below the minimum acceptable operational threshold.

• MAXXUM T4E
• Case IH 240 Series Axial-Flow Combines (7240, 8240, 9240)
• Case IH A8000 / A8800 Sugar Cane Harvesters
• Case IH Magnum tractors
• Case IH Steiger tractors
• Case IH Puma tractors

1. 1

   Verify Ambient Conditions: If operating in extreme sub-zero temperatures, allow the machine to warm up or use a block/compartment heater to see if the code clears.

2. 2

   Check ECU Power and Ground: Inspect the main ECU harness connectors for corrosion, moisture intrusion, or loose ground straps that could cause a voltage drop and skew the internal 5V reference.

3. 3

   Software/Firmware Check: Connect the CNH Electronic Service Tool (EST) to see if a software update is available for the Engine ECU to widen acceptable temperature parameters.

1. 1

   Disconnect batteries

   Disconnect the machine's batteries to prevent electrical arcing.

2. 2

   Locate Engine ECU

   Locate the Engine ECU (typically mounted on the side of the engine block, utilizing vibration isolators).

3. 3

   Unplug ECU connectors

   Carefully release the locking levers on the main wiring harness connectors and unplug them from the ECU.

4. 4

   Remove faulty ECU

   Remove the mounting bolts and remove the faulty ECU.

5. 5

   Install replacement ECU

   Install the replacement ECU and torque the mounting bolts to OEM spec.

6. 6

   Reconnect wiring harnesses

   Reconnect the wiring harnesses, ensuring the locking levers click securely into place.

7. 7

   Reconnect batteries

   Reconnect the batteries.

8. 8

   Program new ECU

   Connect the CNH EST laptop and flash the new ECU with the specific dataset/firmware for your machine's PIN (Product Identification Number) and engine serial number.

9. 9

   Verify repair

   Clear all inactive fault codes and run the engine to verify the repair.