Case IH 19402 – Engine ECU or DCU: CAN timeout error - Urea tank level

Communication failure on the Controller Area Network (CAN) bus. The main controller is not receiving the expected data messages or signals from the DEF (Diesel Exhaust Fluid) / AdBlue tank level sensor within the required timeframe.

• Tier 4b
• Case IH 240 Series Axial-Flow Combines (7240, 8240, 9240)
• Case IH Steiger Tractors (350 to 600 HP models)
• Case IH Magnum Tractors (235 - 340 Series 4)

1. 1

   Visually inspect the DEF/AdBlue tank for severe contamination, dirt, debris, or DEF crystallization that could cause the sensor mechanism to stick or misalign.

2. 2

   Inspect the wiring harness connecting the DEF tank level sensor to the DCU/ECU for chafed wires, corrosion, or moisture inside the connector.

3. 3

   Test the CAN bus lines for continuity and verify the sensor is receiving the correct supply voltage to rule out open circuits or short circuits to ground/high voltage.

1. 1

   Turn off machine

   Turn off the machine, remove the key, and disconnect the battery to prevent electrical shorts.

2. 2

   Locate tank

   Locate the DEF/AdBlue tank assembly.

3. 3

   Clean area

   Thoroughly clean the area around the top of the DEF tank to prevent dirt or crystallized DEF from falling into the tank during removal.

4. 4

   Disconnect harness

   Disconnect the electrical harness connector from the DEF tank level sensor.

5. 5

   Disconnect hoses

   Disconnect the DEF fluid hoses attached to the sending unit (be prepared to catch any spilled DEF with a clean pail).

6. 6

   Remove retaining ring

   Unbolt or unscrew the retaining ring holding the DEF level sensor/header unit to the tank.

7. 7

   Remove sensor

   Carefully pull the old sensor assembly out of the tank.

8. 8

   Install new sensor

   Install the new DEF tank level sensor, ensuring the O-ring/gasket is properly seated to prevent leaks.

9. 9

   Reassemble components

   Reinstall the retaining ring, reconnect the fluid lines, and plug in the electrical harness.

10. 10

    Clear fault code

    Reconnect the battery, turn the key on, and use a diagnostic tool to clear the 19402 fault code. Cycle the key to ensure the CAN timeout error does not return.