Massey Ferguson T4140 – Transmission Control Module (TCU) / Autotronic 4 / DYNA VT (TRANS): Transmission High/Low Range Position Sensor Issue DYNA VT (TRANS)

The transmission control system is detecting that the physical range gear (High/Low or Hare/Tortoise) is not correctly engaged, or the sensor is providing an out-of-tolerance/incorrect signal regarding the gear's position.

• 7614
• 7615
• 7616
• 7618
• 7619
• 7620
• 7622
• 7624
• 7626
• Interim Tier 4 (2012-2015)
• 7600 Series
• 7700 Series
• 7714
• 7726S
• 8600 Series
• 5400 Series
• 6400 Series
• 6700 S
• 7700 S
• 8700 S

1. 1

   Check transmission fluid level and ensure oil is not polluted, as low oil or blocked high-pressure filters can cause engagement issues

2. 2

   Save and document all active and stored error codes to rule out secondary voltage or hydraulic issues

3. 3

   Inspect the wiring harness and connectors going to the range position sensor for supply errors, short circuits, or open wires

4. 4

   Check if the sensor value is out of tolerance ranges, which may indicate a need for recalibration rather than replacement

1. 1

   Fluid & Filter Verification

   Ensure transmission oil levels are adequate and filters are clean.

2. 2

   Electrical Testing

   Locate the Gearbox Range Position Sensor (Hare/Tortoise sensor) on the transmission housing. Disconnect the sensor and inspect the pins for corrosion or damage.

3. 3

   Test the Circuit

   Using a multimeter, verify that the sensor is receiving the correct supply voltage from the Transmission module (Pin 1 is typically supply, Pin 2 is signal).

4. 4

   Recalibration

   If the wiring is intact, use the Massey Ferguson diagnostic tool to attempt a transmission range calibration.

5. 5

   Sensor Replacement

   If the sensor fails electrical testing, or if the calibration fails because the sensor value remains out of tolerance, remove the retaining hardware and replace the range position sensor.

6. 6

   Final Reset

   Clear the T4140 error code from the Autotronic 4 / DYNA VT controller and test-drive the tractor, ensuring it shifts smoothly between High/Low (Hare/Tortoise) ranges.