Massey Ferguson 04.00.85 – Transmission Control Unit (TCU): Issue With Signal From Transmission Mounted Engine Speed Sensor (TRANS) / Issue With Speed Sensor Values (TRANS1)

The controller is receiving erratic, out-of-range, or missing data from the transmission speed sensor, which monitors the rotational speed within the gearbox.

• 7724S
• 5712SL
• 7722S
• 7722
• 5713SL
• 7720S
• 7716
• 7718
• T4
• 7715
• 5710SL
• 7726
• 7726S
• 5711SL
• 7718S
• 7719
• 7714
• 7716S
• 7720
• Tier 4 (2015-2021)
• 7715S
• 7724
• Dyna-4
• Dyna-6
• Dyna-VT
• 5400 Series
• 5425
• 5455
• 5480
• 6400 Series
• 6465
• 6480
• 6499
• 6600 Series
• 6700 Series
• 6700 S Series
• 6613
• 6718 S
• 7600 Series
• 7700 Series
• 7700 S Series
• 7618

1. 1

   Perform diagnostic tests on the sensors using Wintest software to monitor the active and requested values of the forward speed, engine speed, intermediate speed, and PTO speed sensors

2. 2

   Note: Replacing sensors without first performing the listed Wintest diagnostic tests will result in warranty claims being denied

3. 3

   Verify the integrity of the wiring harness and electrical connectors leading to the transmission speed sensor, as physical damage or poor connections can trigger the same signal fault

1. 1

   Verify sensor failure

   Connect a diagnostic laptop with Wintest software to the tractor to verify the sensor values and confirm the sensor itself is the point of failure.

2. 2

   Locate sensor

   Locate the transmission speed sensor on the transmission housing.

3. 3

   Disconnect sensor

   Disconnect the electrical connector from the sensor.

4. 4

   Remove sensor

   Unbolt and remove the faulty speed sensor.

5. 5

   Install replacement sensor

   Install the replacement sensor. (Important Note: If you are replacing an older style sensor with the newer superseded part, you may need to install an adapter harness).

6. 6

   Reconnect sensor

   Reconnect the electrical connector.

7. 7

   Clear codes and test

   Clear the fault codes using the diagnostic tool and test drive the tractor to ensure the transmission shifts correctly and the code does not return.