Case IH 14900 – Transmission Controller: Transmission controller missing

Controller Area Network (CAN) communication error indicating that the main vehicle controller has lost communication with the transmission controller over the CAN bus network.

• Puma/Mid Range Magnum
• Maxxum
• MAXXUM T4E
• Case IH Maxxum Series (MXU115, Maxxum 100, 110, 140)
• Case IH Puma Series (140, 165, 180, 195, 210, 225 CVX)
• Case IH Magnum Series (MX210, MX215, MX230, MX245, MX255, MX275)
• Case IH Steiger Series
• Case IH Farmall Series (with cab and CVT transmissions)
• Case IH Industrial/Construction (580, 585G, 586G, 588G, 570LXT)

1. 1

   Check battery voltage and alternator output, as low voltage can cause modules to drop off the CAN network

2. 2

   Inspect all fuses and relays associated with the transmission controller to ensure the module is receiving power

3. 3

   Inspect the wiring harness between the main controller/cab and the transmission controller for chafed wires, rodent damage, or pinched lines

4. 4

   Test the CAN High and CAN Low lines for continuity, shorts to ground, or shorts to power

5. 5

   Disconnect the transmission controller and inspect the pins for corrosion, moisture, or pushed-out terminals

6. 6

   Verify that the transmission controller is receiving proper power and a solid ground at the connector

1. 1

   Disconnect Power

   Turn off the tractor and disconnect the negative battery cable to prevent electrical shorts.

2. 2

   Access the TCU

   Locate the transmission controller (location varies by model, often found under the right-hand console, under the cab floor, or mounted directly to the transmission housing).

3. 3

   Repair Wiring

   If the diagnostic checks revealed broken CAN wires or poor grounds, repair the wiring harness using OEM-approved splicing methods and heat-shrink tubing. Clean any corroded connectors with electrical contact cleaner.

4. 4

   Replace the Controller

   If the wiring, power, and ground are intact, remove the mounting bolts securing the faulty transmission controller and disconnect the wiring harnesses.

5. 5

   Install New Controller

   Mount the replacement transmission controller and securely plug in the wiring harnesses.

6. 6

   Reconnect Power

   Reconnect the negative battery cable.

7. 7

   Calibration/Programming

   Use dealer-level software (such as the Jaltest Agricultural Equipment Diagnostic Kit or Case IH Electronic Service Tool) to flash the correct software, configure the module to the tractor's specific options, and calibrate the transmission clutches and valves.

8. 8

   Clear Codes

   Clear the 14900 fault code from the system and test drive the tractor to ensure forward/reverse movement is restored and the code does not return.