Case IH 3338 (F-518256-09) - ECU – Engine Control Unit (ECU): CAN communication failure between vehicle controller and ECU controller - TSC1_VE message

The Engine Control Unit (ECU) is not receiving the expected Torque/Speed Control (TSC1) message from the main vehicle controller over the Controller Area Network (CAN) bus within the required timeframe.

• VESTRUM CVX
• Case IH Magnum 235-340 (Series 4)
• Case IH Steiger
• Case IH Puma
• Case IH Farmall
• 240 Series Axial-Flow Combines
• Skid Steer Loaders (SSL) with F5C engines
• Compact Track Loaders (CTL) with F5C engines

1. 1

   Verify that the external power supply, battery voltage, and charging system are functioning correctly, as low voltage can cause CAN communication drops.

2. 2

   Inspect the wiring harness and connectors between the Vehicle Controller (VCM/CCU) and the Engine ECU. Look for pushed-out pins, corrosion, or moisture.

3. 3

   Check the CAN Node A Bus for open circuits, short circuits to ground, or short circuits to battery.

4. 4

   Verify the CAN termination resistors. With the battery disconnected, measure the resistance across the CAN High and CAN Low pins; it should typically read around 60 ohms if both 120-ohm resistors are intact.

5. 5

   Ensure both the ECU and the Vehicle Controller are receiving proper supply voltage and have clean grounds.

1. 1

   Disconnect Power

   Always disconnect the battery before servicing the ECU or CAN bus wiring to prevent electrical spikes.

2. 2

   Repair Wiring

   If the diagnostic checks reveal a faulty wire harness, repair or replace the damaged sections of the CAN twisted pair or the damaged connector terminals.

3. 3

   Restore Power & Clear Codes

   Reconnect the battery, restore supply power, and use the CNH Electronic Service Tool (EST) to clear the fault codes.

4. 4

   Test Operation

   Run the machine to see if the 3338 code returns.

5. 5

   Module Replacement

   If the wiring, termination resistors, and power supplies all test good but the code immediately returns, the fault is likely an internal failure of the CAN controller within either the ECU or the Vehicle Controller. Replace the faulty module as indicated by the service manual's final pinpoint test. Note: A new ECU will require dealer software to flash the correct engine dataset for the specific machine.