Massey Ferguson T256 – TRANS2: Transmission Input Shaft Speed Sensor Signal Fault (TRANS2)

The transmission control module is detecting an irregular, missing, or out-of-range signal from the input shaft speed sensor. This can cause rough shifting, failure to find the correct gear, or erratic speedometer readings.

• 7616
• 5612
• 7622
• Interim Tier 4 (2012-2015)
• 7614
• 5611
• 7615
• 5610
• 5613
• 7620
• 5609
• 7618
• 5608
• 7619
• 7626
• 7624
• 5710SL
• 5711SL
• 5712SL
• 5713SL
• 6400 Series
• 6600 Series
• 6700 Series
• 7714
• 7715
• 7715S
• 7716
• 7716S
• 7718
• 7718S
• 7719
• 7720

1. 1

   Check Sensor Resistance: Unplug the sensor and measure the resistance across Pin 1 (Signal) and Pin 2 (Earth). When stopped, an inductive speed sensor should read approximately 450 Ohms +/- 20.

2. 2

   Check Voltage: Verify that the sensor produces an alternating voltage when the ring gear/shaft is rotating.

3. 3

   Inspect Wiring: Check the sensor status, contacts, harness connections, and wiring for any short circuits (to +12V or 0V) or open circuits.

4. 4

   Check Battery Voltage: Ensure the tractor's battery voltage is stable (between 11V and 16V), as voltage drops can trigger false sensor codes.

1. 1

   Preparation

   Disconnect the tractor's battery before starting work to prevent electrical damage.

2. 2

   Locate and Remove

   Locate the sensor underneath the tractor, threaded into the transmission housing above the differential ring gear. Clean the mounting area and electrical connector thoroughly to prevent dirt from entering the transmission, then unscrew the old sensor.

3. 3

   Install the New Sensor (Air Gap Adjustment)

   Apply a small amount of thread sealant (e.g., Loctite 5922) to the threads of the new sensor. Carefully screw the sensor in fully until it bottoms out against the gear. Unscrew the sensor by exactly ¾ of a turn to set the correct air gap. Tighten the counter-nut to approximately 6 Nm to lock it in place.

4. 4

   Reconnect

   Plug the electrical harness back into the sensor.

5. 5

   System Reset

   Reconnect the battery. Clear the transmission fault codes using the Wintest/EDT software. Alternatively, perform a manual system reset by moving the PowerControl lever to the neutral position, then pressing and releasing the clutch pedal.