Case IH 2701 – ZTC: CAN bus communication error: EEC1 message

The receiving controller (ZTC) is either not receiving the EEC1 message (a CAN timeout) or the specific AEPT signal data within that message is flagged as an error or 'not available' by the engine ECU.

• Steiger T4B
• Maxxum series
• Puma series
• Farmall series
• Axial-Flow combines

1. 1

   Verify J1939 CAN Bus traffic using a CAN monitor or diagnostic tool to look for the EEC1 frame (PGN 61444 / Hex F004) on the network.

2. 2

   Check for accompanying codes to determine if the Engine ECU is offline entirely (causing multiple CAN timeouts) or if only the AEPT signal (SPN 513) is missing.

3. 3

   Inspect the 24V/12V voltage supply and ground at the Engine ECU plugs, as a lack of power will prevent it from broadcasting the EEC1 message.

4. 4

   Check the CAN bus wiring harness between the Engine ECU and the ZTC for chafing, corrosion, or loose connector pins.

1. 1

   Connect Diagnostic Tool

   Connect the CNH Electronic Service Tool (EST) or a J1939 CAN reader to the machine's diagnostic port.

2. 2

   Monitor SPN 513

   Check the live data for SPN 513 (Actual Engine Percent Torque). If the value reads as an error indicator (e.g., 'FE' or 'FF' in hex, meaning not available), the issue is internal to the Engine ECU's torque calculation.

3. 3

   Inspect the Harness

   If the entire EEC1 message is missing, physically inspect the CAN link wiring between the ZTC and the Engine ECU. Disconnect the harness and check for continuity and proper terminating resistance (typically 60 ohms across the CAN High and CAN Low pins).

4. 4

   Repair Wiring

   Repair any broken wires, clean corroded pins, or replace damaged connector pigtails on the CAN bus line.

5. 5

   ECU Verification

   If the wiring is intact and the Engine ECU has proper power and ground but is still not broadcasting the EEC1 message, the Engine ECU may require a software re-flash or replacement.

6. 6

   Clear Codes

   After repairs, cycle the key, clear the fault codes, and verify that the ZTC is successfully receiving the AEPT signal.