Massey Ferguson 04.01.90 – Transmission Control Module (TCU) / TRANS1: Issue With Speed Sensor Values (TRANS1)

The transmission control system is receiving erratic, out-of-range, or missing signals from the transmission speed sensor. This sensor is responsible for measuring the rotational speed of the transmission shafts and transmitting that data to the controller to manage shifting and display ground speed.

• 7724S
• 5712SL
• 7722
• 7722S
• 5713SL
• 7720S
• 7716
• 7718
• T4
• 7715
• 5710SL
• 7726
• 7726S
• 5711SL
• 7718S
• 7719
• 7714
• 7716S
• 7720
• Tier 4 (2015-2021)
• 7715S
• 7724
• 4707
• 4708
• 4709
• 4710
• 5608
• 5609
• 5610
• 5611
• 5612
• 5613
• 7614
• 7615
• 7616
• 7618
• 7619
• 7620
• 7622
• 7624
• 7626
• T4 Emissions Generation (2017-2023)

1. 1

   Inspect the wiring harness leading to the transmission speed sensor for open circuits, chafed wires, or damage to the sensor cable sheath.

2. 2

   Disconnect the sensor connector and the chassis control module connector to inspect the pins for corrosion, moisture, or loose connections.

3. 3

   Ensure the sensor itself is not physically loose in the transmission housing.

4. 4

   Use the tractor Dash Control Center or Wintest diagnostic software to monitor the active and requested speed values in real-time for erratic spikes or drops to zero.

5. 5

   Ensure the transmission oil temperature is at normal operating range (between 35C and 45C) to see if the fault is temperature-dependent.

1. 1

   Preparation

   Park the tractor on flat, level ground, engage the parking brake, and turn off the engine.

2. 2

   Access the Sensor

   Locate the transmission speed sensor on the side of the transmission housing. Note: On larger frame models (like the 6400, 7600, and 7700 series), accessing the sensor may require removing one of the rear wheels/tyres for adequate clearance.

3. 3

   Removal

   Disconnect the electrical connector from the sensor. Unbolt or unthread the faulty speed sensor from the transmission housing. Have a catch pan ready, as a small amount of transmission fluid may weep from the port.

4. 4

   Installation

   Thread the new OEM speed sensor into the housing and tighten to the manufacturer's torque specification. Reconnect the electrical harness securely.

5. 5

   Reassembly

   Reinstall the rear wheel if it was removed, torquing the lug nuts to spec.

6. 6

   Clear Codes & Calibrate

   Turn the key on and use the diagnostic interface to clear the 04.01.90 fault code. Warm the tractor up until the transmission oil is between 35C and 45C, and perform a transmission clutch calibration (Dyna-4/Dyna-6) to ensure smooth engagement with the new sensor readings.