Case IH 2255 – ZDC Controller: ZDC - CAN message Extswitch00 counter incorrect

A Controller Area Network (CAN) bus communication error where the CAN message counter for an external switch (Extswitch00) is not incrementing as expected. This indicates that the controller is either not receiving the signal from the switch module, or the data packets are corrupted due to a wiring or module fault.

• Steiger T4B
• Steiger 370
• Steiger 420
• Steiger 470
• Steiger 500
• Steiger 540
• Steiger 580
• Steiger 620
• Quadtrac
• Rowtrac
• AFS Connect models

1. 1

   Fuse Inspection: Check fuse F-101 (5A, switched key power) and fuse F-102 (7.5A, main power) in the cab power distribution module.

2. 2

   CAN Bus Wiring Check: Inspect the CAN High and CAN Low communication lines between the external switch modules (e.g., the multicontroller armrest or cruise control switches) and the ZDC controller for continuity, chafing, or shorts to ground.

3. 3

   Connector Inspection: Check the harness connectors at the ZDC controller and the external switch module for pushed-out pins, moisture, or corrosion.

4. 4

   Switch Plausibility Test: Test the physical switches on the armrest. If a switch is physically stuck or has been depressed for an implausible amount of time, the CAN counter may register an error.

1. 1

   Power Down

   Turn off the tractor, remove the key, and disconnect the battery ground to ensure safety while working on the CAN bus system.

2. 2

   Verify Power Supply

   Locate the cab power distribution module. Inspect and replace fuses F-101 (5A) and F-102 (7.5A) if they are blown. If a fuse is blown, check the circuit for a short before restoring power.

3. 3

   Clean Connections

   Disconnect the wiring harness at the ZDC controller and the suspected external switch module. Spray the contacts with electrical contact cleaner, ensure no pins are bent, and securely reconnect them.

4. 4

   Repair Wiring

   If the diagnostic continuity check revealed a break or high resistance in the CAN bus wires between the switch and the ZDC, repair or replace the affected harness section.

5. 5

   Replace Faulty Component

   If the wiring and power supply are intact but the CAN counter error persists, the external switch module itself is likely failing to broadcast its status and must be replaced.

6. 6

   Clear Codes

   Reconnect the battery, power on the tractor, and use a diagnostic tool (such as the Case IH EST or Jaltest) to clear the 2255 fault code. Test the switches and CVT operation to ensure the code does not return.