Case IH 2250 – ZDC: CAN message AXCDN1 checksum incorrect

The AXCDN1 CAN message is responsible for transmitting signals related to the front axle / four-wheel drive engagement and the differential lock from the engine/transmission interface. When the checksum of this message is incorrect, the system detects a data transmission error. As a safety precaution, the tractor will default to a protective state, and the maximum driving speed will be limited.

• Steiger T4B
• Case IH Steiger (CVT configurations)
• Case IH Puma CVX
• Puma 165 CVX
• Case IH Maxxum CVX
• Maxxum 150 CVX
• Case IH Magnum CVT
• Magnum 380 CVT

1. 1

   Check the CAN bus wiring between the ZDC and the VCM/UCM for open circuits, shorts to ground, or shorts to power.

2. 2

   Inspect the multi-pin connectors at the ZDC module for corrosion, moisture, or backed-out pins.

3. 3

   Measure the CAN network resistance with the battery disconnected (it should typically read around 60 ohms if both terminating resistors are intact).

4. 4

   Verify if the calibration values are outside of their limits, which can cause the system to revert to standard default values and throw checksum errors.

1. 1

   Connect Diagnostic Tool

   Hook up the Case IH Electronic Service Tool (EST) to verify that code 2250 is active in the ZDC module.

2. 2

   Isolate the CAN Circuit

   Disconnect the ZDC and the VCM. Use a multimeter to perform continuity and short-to-ground tests on the CAN High and CAN Low wires.

3. 3

   Repair Wiring

   If a break or short is found in the harness (especially near articulation joints on Steiger models or under-cab routing on Puma/Magnum models), repair the wiring using OEM-approved splice kits.

4. 4

   Clean and Reseat

   If the wiring tests good, thoroughly clean the ZDC connector pins with contact cleaner, apply dielectric grease, and securely reseat the connectors.

5. 5

   Reflash/Update

   Check the Case IH EST for any available software updates for the ZDC. A software reflash can often resolve erroneous checksum calculation faults.

6. 6

   Clear and Test

   Clear the fault codes. Perform a test drive, engaging the front-wheel drive and differential lock, to ensure the maximum speed limitation has been lifted and the code does not return.