Case IH 19345 (F-518747-09) - ECU – Engine Control Unit (ECU): CAN timeout error from heater control unit (HCU) - HCU2EDC1

The Engine Control Unit (ECU) has lost Controller Area Network (CAN) bus communication with the Heater Control Unit (HCU). Specifically, the ECU is detecting a timeout of the CAN-Receive-Frame "HCU2EDC1" (Heater Control Unit to Electronic Diesel Control 1). The HCU is responsible for controlling and monitoring the line heaters for the Diesel Exhaust Fluid (DEF) / AdBlue hoses in the SCR emissions system.

• VESTRUM CVX
• Case IH T7 Series (Tier 4B / Urea Engine)
• Case IH Vestrum Series (e.g., Vestrum 100, 110)
• Case IH Farmall Series (e.g., 95A Tier 4B)
• Case Construction 580SN Backhoe Loaders (Tier 4B)

1. 1

   Inspect the CAN cable/wiring harness between the HCU and the ECU for disconnected, broken, or rubbed-through wires

2. 2

   Test the CAN communication lines (HCU Can Hi / HCU Can Lo) for open circuits, short circuits to positive (battery voltage), or short circuits to ground

3. 3

   Verify that the HCU is receiving proper power supply (Terminal 30) and ground (Terminal 31)

4. 4

   Verify the CAN configuration in the Heater Control Unit via a diagnostic service tool, as a wrong configuration can trigger communication timeouts

1. 1

   Turn off the machine and locate the Heater Control Unit (HCU) and the Engine Control Unit (ECU).

2. 2

   Disconnect the wiring harness at the HCU and inspect the pins for corrosion, moisture, or pushed-back terminals.

3. 3

   Using a multimeter, perform continuity and short-to-ground tests on the CAN bus wiring connecting the HCU to the ECU.

4. 4

   Repair any damaged wiring or connectors found in the CAN bus circuit.

5. 5

   If the wiring is completely intact, the CAN controller inside the HCU is likely defective.

6. 6

   Replace the Heater Control Unit (HCU).

7. 7

   Turn the starter switch to the ON position.

   The system is designed to recover automatically if a normal signal is received.

8. 8

   Clear the inactive fault codes using a Case IH EST (Electronic Service Tool).