Case IH 19346 (F-518748-09) - ECU – Engine Control Unit (ECU): CAN timeout error from heater control unit (HCU) - HCU2EDC2

The Engine Control Unit (ECU) has lost Controller Area Network (CAN) communication with the Heater Control Unit (HCU) for a specified timeout period.

• VESTRUM CVX
• Puma
• Maxxum
• Optum
• Vestrum
• Farmall
• 580SN Backhoe Loaders
• SV340B Skid Steers

1. 1

   Check Power and Ground: Verify that the Heater Control Unit (HCU) is receiving proper operating voltage. An under-voltage condition at the HCU will cause it to drop off the CAN network.

2. 2

   Inspect the CAN Bus Wiring: Check the CAN network wiring harness (HCU Can Lo / HCU Can Hi) connecting the HCU to the ECU. Look for disconnected cables, broken wires, open circuits, short circuits to ground, or short circuits to positive.

3. 3

   Check Connectors: Inspect the HCU and ECU connectors for corrosion, moisture, or pushed-out pins that could interrupt the CAN signal.

4. 4

   Verify CAN Configuration: Ensure the CAN configuration in the Heater Control Unit is correct.

1. 1

   Power Down

   Turn off the machine's starter switch and disconnect the battery to ensure safety while working on the electrical system.

2. 2

   Locate the HCU

   Locate the Heater Control Unit, which is typically mounted near the DEF/AdBlue tank and supply module.

3. 3

   Repair Wiring

   If the diagnostic checks revealed a broken wire or short circuit in the CAN lines or power supply lines, repair or replace the affected section of the wiring harness.

4. 4

   Replace the HCU

   If the wiring harness, power, and ground are all intact and functioning normally, the CAN controller inside the HCU is likely defective. Remove the faulty HCU and install a new unit.

5. 5

   System Recovery

   Reconnect the battery and turn the starter switch to the ON position. The system is designed to recover automatically if a normal CAN signal is successfully received from the HCU.

6. 6

   Clear Codes

   Use a diagnostic service tool to clear the inactive fault code from the ECU's memory.