Massey Ferguson 4.X.85 – TRANS1: Issue With Speed Sensor Values

Discrepancy between the Engine Speed Sensor (X481) and the Intermediate Speed Sensor (X483), indicating a slip greater than 10% for more than 700 ms between engine speed and intermediate speed.

• 5710SL
• 5711SL
• 5712SL
• 5713SL
• T4
• 5400 Series
• 5600 Series
• 5608
• 5609
• 5610
• 5611
• 5612
• 5613
• 5700 Series
• 5700SL Series
• 6400 Series
• 6700 Series
• 6713
• 7600 Series
• 7700 Series
• 7714
• 7715
• 7716
• 7718
• 7719
• 7720
• 7722
• 7724
• 7726
• 8400 Series
• 8600 Series
• 8700 Series

1. 1

   Connect Wintest diagnostic software to monitor live active and requested values for Engine Speed (X481) and Intermediate Speed (X483)

2. 2

   Observe live data while driving to identify if a sensor signal is dropping, spiking, or providing erratic readings

3. 3

   Inspect wiring harnesses and connectors for sensors X481 and X483 for chafing, corrosion, or short circuits (e.g., short to +12V or ground)

4. 4

   Verify if actual mechanical transmission slippage is occurring (e.g., clutch pack slipping), which would legitimately trigger the slip code

1. 1

   Access the Sensors

   Locate the Engine Speed Sensor (X481) and the Intermediate Speed Sensor (X483) on the transmission housing.

2. 2

   Inspect the Installation

   Remove the suspect sensor and check the tip for metallic debris or damage, which can interfere with the magnetic pickup. Ensure the sensor's working range/gap is correct.

3. 3

   Repair Wiring

   If the Wintest software or multimeter tests reveal an open or short circuit, repair the affected section of the transmission wiring harness.

4. 4

   Replace the Sensor

   If the wiring is intact but the sensor fails the Wintest diagnostic test, replace the faulty sensor (X481 or X483) with a genuine OEM part.

5. 5

   Clear and Test

   Reconnect the diagnostic tool, clear the 4.X.85 fault code, and perform a test drive to ensure the engine and intermediate speeds remain synchronized without triggering the 700 ms / 10% slip threshold.