Massey Ferguson 04.1.90 – TRANS: Issue With Speed Sensor Values (TRANS)

The transmission controller is detecting erratic, implausible, or missing signals from the transmission speed sensor. This means the sensor's output does not match the expected parameters for the tractor's current operating state, which can lead to shifting issues, limp mode, or loss of speed readouts.

• 4707
• 4708
• 4709
• 4710
• T4 (2015-2021)
• 3000 / 3100 / 3600 Series
• 5400 / 5600 / 5700 Series
• 6100 / 6200 / 6400 / 6600 Series
• 7600 / 7700 Series
• 8100 Series

1. 1

   Connect the tractor to a diagnostic tool and use Wintest software to monitor live data of the forward, engine, intermediate, and PTO speed sensors.

2. 2

   Inspect the wiring harness and electrical connector at the sensor for corrosion, moisture, or physical damage such as chafed wires.

3. 3

   Perform a sensor swap test by temporarily interchanging the transmission speed sensor with the identical engine speed sensor (located on the bell housing) to see if the fault follows the sensor, confirming a faulty sensor rather than a wiring issue.

1. 1

   Locate the Sensor

   The transmission speed sensor is typically located on the right side of the center housing or at the rear of the transmission. You may need to remove the cab floor mat and access panel depending on the specific tractor model.

2. 2

   Clean the Area

   Thoroughly clean the area around the sensor to prevent dirt from falling into the transmission housing when the sensor is removed.

3. 3

   Disconnect

   Unplug the electrical connector from the sensor.

4. 4

   Remove

   Unscrew the sensor from the transmission housing. Have a rag ready, as a small amount of transmission fluid may weep from the port.

5. 5

   Install

   Thread the new transmission speed sensor into the housing. (If the sensor has a specific depth/air-gap requirement, follow the exact thread depth noted in your specific model's manual, though most modern MF sensors are fixed-depth threaded units).

6. 6

   Reconnect

   Plug the electrical connector back in, ensuring the weather seal clicks into place.

7. 7

   Clear Codes

   Use the tractor's onboard diagnostic menu or Wintest software to clear the 04.1.90 fault code. Test drive the tractor to verify the transmission shifts correctly and the code does not return.