Massey Ferguson T115 – Transmission Controller (Autotronic 5): Issue With Speed Sensor Values (TRANS1)

Theoretical forward speed sensor - No speed detected and current intermediate speed > 0. Triggers when the transmission controller detects that the tractor is moving (via the intermediate speed sensor) but the theoretical forward speed sensor (TR4) is reporting zero speed. The system reacts by disengaging all ranges for 6 seconds (coasting) and then re-engaging the range that was active before the error, while sounding an active buzzer.

• 7616
• 5612
• 7622
• Interim Tier 4 (2012-2015)
• 7614
• 5611
• 7615
• 5610
• 5613
• 7620
• 5609
• 7618
• 5608
• 7619
• 7626
• 7624
• 5425
• 5455
• 5465
• 5710SL
• 5711SL
• 5712SL
• 5713SL
• 6445
• 6455
• 6460
• 6480
• 6490
• 6615
• 6713 S
• 6718 S
• 7714
• 7715
• 7718
• 7720
• 7726

1. 1

   Connect the tractor to the Wintest diagnostic software to verify the sensor status and read live data.

2. 2

   Disconnect the TR4 sensor (located above the differential ring gear) and measure the resistance across Pin 1 (Signal) and Pin 2 (Earth). When stopped, the inductive sensor should read 450 Ohms +/- 20. An open circuit indicates a dead sensor.

3. 3

   Measure the output while the ring gear is rotating. The sensor should produce an alternating voltage (AC).

4. 4

   Inspect the wiring harness, contacts, and connections between the sensor and the Autotronic 5 controller for shorts, breaks, or corrosion.

1. 1

   Locate the Sensor

   The TR4 Theoretical Forward Speed Sensor is located above the differential ring gear.

2. 2

   Remove the Old Sensor

   Disconnect the wiring harness and unscrew the faulty sensor.

3. 3

   Prepare the New Sensor

   Apply a small amount of Loctite 5922 to the threads of the new sensor.

4. 4

   Set the Air Gap

   Fully screw the new sensor in until it bottoms out against the differential gear. Unscrew the sensor by exactly ¾ of a turn to establish the correct air gap.

5. 5

   Secure the Sensor

   Tighten the counter-nut to approximately 6 Nm.

6. 6

   Reset the System

   To clear the fault and reset the transmission system, move the PowerControl lever to the neutral position, then press and release the clutch pedal.