Case IH 2722 – ZTC: CAN bus communication error

The transmission controller is experiencing a timeout or error receiving the PTCTL2 (Powertrain Control Message 2) CAN message. The specific signal missing or invalid within this message is the CDLS (Central Differential Lock State), meaning the controller cannot verify the current state of the central differential lock.

• Steiger T4B
• Case IH Steiger CVT
• Case IH Puma CVX / Puma LWB
• Case IH Magnum CVT
• Case IH Maxxum CVT

1. 1

   Check for accompanying ZF transmission CAN faults such as 517248 (FCAN_ERR_PTCTL2) or 517250 (FCAN_PTCTL2_CRC_CHECK), which indicate the PTCTL2 message is timing out or failing its cyclic redundancy check

2. 2

   Test the CAN bus network wiring between the ZTC and the main User Controller (UC) for continuity, open circuits, or short circuits to ground/power

3. 3

   Verify the health of the CAN bus terminating resistors (typically 60 ohms across the CAN High and CAN Low pins when the battery is disconnected)

4. 4

   Ensure the User Controller (which broadcasts the PTCTL2 message) has proper voltage and ground, as a controller dropping offline will cause this timeout

1. 1

   Disconnect Power

   Disconnect the negative battery terminal before servicing the electrical system to prevent module damage.

2. 2

   Access the ZTC and UC

   Locate the ZTC (Transmission Controller) and the main User Controller on the machine.

3. 3

   Harness Inspection & Repair

   Trace the CAN bus wiring harness between the two modules. Look for chafed wires, corrosion in the connectors, or backed-out pins. Repair any damaged sections of the harness.

4. 4

   Replace Terminating Resistors (If Applicable)

   If the CAN bus resistance is out of specification (not 60 ohms), locate and replace the faulty CAN terminator.

5. 5

   Software/Module Replacement

   If the wiring harness and resistors are perfectly intact, the User Controller may be failing to broadcast the CDLS signal, or the ZTC may have a failed CAN transceiver. The modules will need to be tested with a dealer service tool (EST) to determine which module requires a software re-flash or physical replacement.

6. 6

   Clear Codes

   Reconnect the battery, cycle the key, and use the diagnostic tool to clear the passive error messages.