Case IH 2194 – ZDC (Transmission Controller): ZDC - CAN message AXCDN1 timeout

The ZDC (Transmission Controller) stops receiving the AXCDN1 message over the CAN bus within the expected timeframe, which carries data regarding the 4WD and Differential Lock statuses.

• Steiger T4B
• Case IH Puma CVT series
• Case IH Maxxum CVT series
• Case IH Magnum CVT series
• Case IH Steiger AFS Connect CVT series

1. 1

   Verify that the Axle Controller is receiving proper battery voltage and has a clean ground.

2. 2

   Perform a CAN Bus resistance test at the diagnostic port with the tractor powered off and battery disconnected (should read approximately 60 ohms).

3. 3

   Visually inspect the wiring harness running between the Axle Controller and the ZDC for chafing, pinch points, or rodent damage.

4. 4

   Disconnect harnesses at both the ZDC and Axle Controller to check for pushed-out pins, corrosion, or moisture intrusion.

5. 5

   Use the Case IH Electronic Service Tool (EST) to check for other CAN timeout codes to determine if the entire CAN bus is shorted or if the issue is isolated to the Axle Controller.

1. 1

   Isolate the Circuit

   Turn off the key switch and disconnect the negative battery cable.

2. 2

   Clean and Reseat Connectors

   Locate the Axle Controller and the ZDC. Disconnect the main harness connectors. Spray the pins and receptacles with a high-quality electrical contact cleaner. Allow them to dry, apply dielectric grease to the seals (not directly on the pins), and firmly reconnect them.

3. 3

   Perform Continuity Testing

   If the code persists, disconnect the modules again. Using a multimeter, test the CAN High and CAN Low wires for continuity from the Axle Controller connector to the ZDC connector. Repair any breaks in the wire using OEM-approved splicing methods.

4. 4

   Test for Shorts

   Test the CAN High and CAN Low wires for continuity to ground (chassis) and to each other. If a short is found, trace the harness to locate the rub-through and repair the wiring.

5. 5

   Module Replacement

   If the wiring harness tests perfectly, power and ground to the Axle Controller are verified, and the terminating resistors are intact, the Axle Controller itself has likely suffered an internal failure and is no longer broadcasting the AXCDN1 message. Replace the Axle Controller.

6. 6

   Clear and Test

   Reconnect the battery. Connect the Case IH EST, clear the 2194 fault code, and test drive the tractor. Engage and disengage the 4WD and Differential Lock to verify the AXCDN1 message is being successfully transmitted and received.