Case IH 2691 – ZTC Controller: ZTC and AXCTL1 CAN message counter incorrect or timing out

The fault code indicates a CAN bus communication error, specifically that the rolling counter for the AXCTL1 (Axle Control / Drivetrain Control) CAN message is incorrect or timing out. The ZTC module is either receiving corrupted data from the drivetrain/axle controller or the communication line is experiencing interference/drops.

• Steiger T4B
• Steiger
• Quadtrac
• Rowtrac

1. 1

   Check power and ground to the ZTC controller, specifically the fuses supplying it on the cab power distribution module.

2. 2

   Inspect the CAN bus wiring harness between the ZTC controller and the axle/drivetrain controller for chafed wires, corrosion at connector pins, or loose connections.

3. 3

   Check for software mismatches between the ZTC and drivetrain controllers.

4. 4

   Check for related CAN timeout codes (such as Checksum errors or EEC1/PTCTL1 timeouts) which would indicate a broader CAN bus failure.

1. 1

   Power Down

   Turn off the tractor and disconnect the battery to ensure safety while working on the electrical system.

2. 2

   Inspect Fuses

   Locate the Cab Power Distribution Module. Inspect and test the fuses designated for the ZTC Controller (identified in schematics as F2_10, F2_14, F6_2, F6_6, etc.). Replace any blown fuses.

3. 3

   Harness Repair

   Disconnect the harness at the ZTC controller. Clean the contacts with electronic contact cleaner. If any CAN high or CAN low wires are damaged, repair the wiring using OEM-approved splicing techniques to maintain the twisted-pair integrity of the CAN lines.

4. 4

   Software Flash (Dealer Level)

   If the wiring is intact, connect the Case IH EST (Electronic Service Tool) and verify the software versions of the ZTC and the drivetrain controller. Flash the latest firmware to ensure compatibility.

5. 5

   Module Replacement

   If the wiring is perfect, software is up to date, and the ZTC controller still fails to process the AXCTL1 message correctly, the ZTC controller itself may have an internal CAN transceiver failure and must be replaced.