Massey Ferguson 4.03.40 – Transmission Control Unit (TCU) / TRANS1: Issue With Speed Sensor Values (TRANS1)

The transmission control system is detecting an irregular, missing, or out-of-range signal from the transmission speed sensor.

• 5710SL
• 5711SL
• 5712SL
• 5713SL
• T4
• 5608
• 5609
• 5610
• 5611
• 5612
• 5613
• 6613
• 6614
• 6615
• 6616
• 6713
• 6714
• 6715
• 6716
• 6718
• 7614
• 7615
• 7616
• 7618
• 7619
• 7620
• 7622
• 7624
• 7626
• 7714
• 7715
• 7715S
• 7716
• 7716S
• 7718
• 7718S
• 7719
• 7720
• 7720S
• 7722
• 7722S
• 7724
• 7724S
• 7726
• 7726S

1. 1

   Use the Massey Ferguson Wintest software to monitor the sensor outputs and perform diagnostic tests to confirm the failure.

2. 2

   Check the sensor harness connections, wiring, and contacts for damage, corrosion, or loose pins.

3. 3

   With the tractor stopped, test the inductive sensor's resistance using a multimeter across Pin 1 (Signal) and Pin 2 (Earth). A healthy sensor typically reads 450 Ohms (+/- 20 Ohms) or 540 Ohms, depending on the exact part number.

4. 4

   Check for alternating voltage (AC) output from the sensor while the internal ring gear or shaft is rotating.

1. 1

   Locate sensor

   Locate the transmission speed sensor (often threaded into the transmission housing above the differential ring gear or input shaft).

2. 2

   Remove old sensor

   Disconnect the electrical harness and unscrew the old sensor.

3. 3

   Apply sealant

   Apply a small amount of thread sealant (such as Loctite 5922) to the threads of the new sensor.

4. 4

   Set initial air gap

   Fully screw the sensor in by hand until it gently bottoms out against the internal gear.

5. 5

   Adjust air gap

   Carefully unscrew the sensor by exactly ¾ of a turn to establish the correct air gap.

6. 6

   Tighten counter-nut

   Hold the sensor steady in this position and tighten the counter-nut to approximately 6 Nm.

7. 7

   Reconnect harness

   Reconnect the wiring harness.

8. 8

   Reset system

   Reset the system/clear the fault code. On some Dyna-6 models, this can be done by moving the PowerControl lever to the neutral position, then pressing and releasing the clutch pedal.