Massey Ferguson 4.02.B8 – TRANS1: Issue With Intermediate Speed Sensor Values

The transmission controller is detecting an anomaly where there is no intermediate speed detected while the current forward speed is greater than 0, or there is an illogical discrepancy between the intermediate speed and the forward speed depending on the selected range.

• 5710SL
• 5711SL
• 5712SL
• 5713SL
• T4
• 4707
• 4708
• 4709
• 4710
• 5608
• 5609
• 5610
• 5611
• 5612
• 5613
• 7614
• 7615
• 7616
• 7618
• 7619
• 7620
• 7622
• 7624
• 7626
• 7714
• 7715
• 7715S
• 7716
• 7716S
• 7718
• 7718S
• 7719
• 7720
• 7722
• 7724
• 7726

1. 1

   Visually inspect the wiring harness and connectors leading to the intermediate speed sensor (TR25/X483) for backed-out pins, probed wires, corrosion, or physical damage.

2. 2

   Perform a resistance test on the disconnected sensor; a healthy inductive speed sensor should read approximately 450 Ohms (+/- 20 Ohms) when stopped. An open circuit indicates internal failure.

3. 3

   Check for alternating voltage output from the sensor while the internal gear is rotating.

4. 4

   Use Massey Ferguson Wintest diagnostic software to monitor the active intermediate speed sensor value in RPM (TR25) while driving to check for intermittent signal dropouts.

1. 1

   Locate the Sensor

   Locate the intermediate speed sensor on the side of the transmission housing.

2. 2

   Removal

   Disconnect the electrical connector. Loosen the counter-nut or retaining bolt and carefully extract the sensor from the transmission housing.

3. 3

   Installation & Air Gap Adjustment

   Apply a small amount of thread sealant (e.g., Loctite 5922) to the threads of the new sensor. Carefully screw the sensor in by hand until it gently bottoms out against the internal gear. Unscrew the sensor by exactly ¾ of a turn to set the correct air gap. Tighten the counter-nut to approximately 6 Nm.

4. 4

   Reconnect

   Plug the electrical connector back in, ensuring it clicks securely into place.

5. 5

   Clear Codes

   Reset the system. On some Autotronic 5 systems, this can be done by moving the PowerControl lever to the neutral position, then pressing and releasing the clutch pedal, or by using the dealer diagnostic tool to clear the TRANS1 module codes.