Case IH 3009 – Engine Control Unit (ECU) / Engine Controller (EDC): Coolant Temperature Sensor -(via CAN) No Signal

The control module is not receiving a valid temperature reading from the engine coolant temperature sensor over the Controller Area Network (CAN) bus. The signal is either missing, null, or failing a plausibility check.

• Magnum 215
• Magnum 235
• Magnum 245
• Magnum 255
• Magnum 275
• Magnum 305
• Magnum 335
• Magnum 340
• Steiger 280
• Steiger 330
• Steiger 335
• Steiger 350
• Steiger 400
• Steiger 450
• Steiger 500
• Steiger 550
• Steiger 600
• MX210 to MX305
• MXM120 to MXM190
• 580 Super N
• 570NXT
• SV-series
• CX100
• MX100C

1. 1

   Restart the system/machine to verify if the code is active or stored, as the ECU performs a CAN plausibility check on startup

2. 2

   Check the wiring harness connecting the coolant temperature sensor to the Engine ECU for broken wires, chafing, or disconnected plugs

3. 3

   Test the sensor circuit for a short to ground or a short circuit to an external power source

4. 4

   Ensure the CAN bus communication lines are intact and that there are no broader CAN network failures affecting multiple sensors

1. 1

   Turn off the machine and disconnect the battery

   Turn off the machine and disconnect the battery to protect the ECU.

2. 2

   Locate the Coolant Temperature Sensor

   Locate the Coolant Temperature Sensor on the engine block/thermostat housing.

3. 3

   Inspect the sensor's electrical connector

   Disconnect the sensor's electrical connector and inspect the pins for corrosion, moisture, or damage. Clean with contact cleaner if necessary.

4. 4

   Trace and repair the wiring harness

   Trace the wiring harness back to the Engine ECU, repairing any damaged sections of the wire or replacing the pigtail connector if it is compromised.

5. 5

   Verify sensor failure

   If the wiring and CAN network are verified to be in good condition, the sensor itself has failed internally.

6. 6

   Drain coolant

   Drain a small amount of coolant from the system to prevent spillage (if the sensor is mounted below the coolant level).

7. 7

   Replace the sensor

   Unthread the defective sensor and install the replacement.

8. 8

   Reassemble and verify

   Reconnect the wiring harness, refill the coolant, reconnect the battery, and start the engine to verify the fault code clears.