Massey Ferguson T4108 – Transmission Control Unit (TCU) / Autotronic 4 transmission controller (TRANS): Transmission High/Low Range Position Sensor Issue

The code is triggered when the controller detects an 8.5 V supply error to the sensor, a general signal error, or when the sensor's calibration value falls out of the acceptable tolerance range.

• 7622
• Interim Tier 4 (2012-2015)
• 7614
• 7615
• 7620
• 7616
• 7618
• 7619
• 7626
• 7624
• 8650
• 8670
• 8690

1. 1

   Test the power supply circuit to the X17 Hare/Tortoise range position sensor to ensure the controller is supplying exactly 8.5 Volts.

2. 2

   Inspect the wiring harness and connectors between the X17 sensor and the Autotronic 4 transmission controller for chafed wires, shorts to ground, or open circuits.

3. 3

   Verify if the transmission range shift mechanism is physically binding.

4. 4

   Check if the sensor simply needs to be recalibrated via the dealer diagnostic tool due to a calibration error.

1. 1

   Access the Sensor

   Locate the X17 Hare/Tortoise range position sensor on the Dyna VT transmission housing.

2. 2

   Repair Wiring

   If the diagnostic checks revealed a short or break in the 8.5V reference wire or signal wire, repair the harness and clean the connector pins.

3. 3

   Replace the Sensor

   If the wiring is intact and the 8.5V supply is confirmed, but the signal error persists, the X17 sensor itself has failed internally. Remove the mounting hardware, extract the old sensor, and install the new unit.

4. 4

   Recalibrate

   After installing a new sensor, you must perform a transmission calibration procedure using the Massey Ferguson/AGCO diagnostic tool so the Autotronic 4 controller can learn the new sensor's physical end-stops (Hare and Tortoise positions).

5. 5

   Clear Codes

   Clear the T4108 code from the transmission controller and test drive the tractor to ensure smooth shifting between High (Hare) and Low (Tortoise) ranges.