Case IH 544-02 - VCM – Vehicle Control Module (VCM): Invalid reference torque value received from engine controller

The receiving module is successfully communicating on the CAN bus, but the specific Engine Reference Torque signal being broadcasted by the engine controller is outside of the expected parameters or marked as invalid (SPN 544, FMI 02).

• MAGNUM AFS Connect
• Magnum
• Steiger
• Puma
• Maxxum
• Optum
• Combines
• Sprayers

1. 1

   Check for active faults in the Engine ECM using the CNH Electronic Service Tool (EST)

2. 2

   Inspect the integrity of the J1939 CAN bus communication lines between the Engine ECM and the VCM

3. 3

   Verify if there is a software mismatch or an available software update for the Engine ECM or VCM

1. 1

   Connect Diagnostic Tool

   Connect the CNH EST to the machine's diagnostic port and perform a full system scan.

2. 2

   Address Primary Engine Faults

   If the Engine ECM has active faults related to fueling, sensors, or internal calculations, diagnose and repair those first. The 544-02 code is often a secondary symptom of an engine derate or calculation error.

3. 3

   Visual Wiring Inspection

   If no other engine codes are present, physically inspect the J1939 CAN bus wiring harness between the ECM and VCM. Look for chafed wires, corrosion, or pushed-back pins in the connectors.

4. 4

   Test CAN Bus

   Measure the CAN bus resistance (should be approx. 60 ohms with batteries disconnected) to ensure terminating resistors are intact.

5. 5

   Update Software

   If the wiring is intact and the signal is still invalid, reflash/update the software on both the Engine ECM and the VCM to the latest OEM calibration.

6. 6

   Clear and Test

   Clear all fault codes and test operate the machine under load to verify the fault does not return.