Massey Ferguson 4.X.6A – TRANS1: Issue With Range 4 Solenoid Valve (TRANS1)

The transmission controller has detected an electrical fault in the circuit for the Range 4 solenoid valve (L55). This indicates an open circuit, a short circuit to +12V or ground, or an inconsistency between the Range 4 solenoid valve (L55) and the Range 4 position switch (L59).

• 5710SL
• 5711SL
• 5712SL
• 5713SL
• T4
• 5400 Series
• 5608
• 5609
• 5610
• 5611
• 5612
• 5613
• 6400 Series
• 6700 Dyna 6
• 7614
• 7615
• 7616
• 7617
• 7618
• 7714
• 7715
• 7716
• 7718
• 7719
• 7720
• 7722
• 7724
• 7726

1. 1

   Inspect the wiring harness running from the Autotronic 5 controller to the transmission's right-hand hydraulic cover for chafed wires, melted insulation, or pinched harnesses.

2. 2

   Disconnect the electrical connector at the L55 Range 4 solenoid valve and check for water ingress, corrosion, or pushed-out pins.

3. 3

   Measure the resistance of the L55 solenoid valve coil using a multimeter to check for an internal open or short circuit.

4. 4

   Test the wiring between the Autotronic 5 module and the L55 connector for continuity, short to ground (0V), and short to power (+12V).

5. 5

   Verify the operation of the Range 4 position switch (L59) to ensure it is not failing or sticking, which triggers an inconsistency fault.

1. 1

   Prepare tractor for service

   Park the tractor on a level surface, engage the parking brake, lower any implements, and turn off the engine. Disconnect the battery to prevent electrical shorts.

2. 2

   Locate valve block

   Locate the transmission control valve block. On Dyna-4 and Dyna-6 gearboxes, the range solenoid valves are located on the right-hand side of the gearbox housing.

3. 3

   Identify solenoid

   Identify the L55 solenoid valve, which controls Range 4.

4. 4

   Clean area

   Clean the area around the solenoid valve thoroughly to prevent dirt from entering the hydraulic system.

5. 5

   Disconnect wiring

   Disconnect the electrical connector from the L55 solenoid valve.

6. 6

   Remove hardware

   Remove the retaining screws and the flange holding the solenoid valve in place.

7. 7

   Remove solenoid

   Carefully pull the faulty solenoid valve out of the valve block. Have a rag ready to catch any residual hydraulic oil.

8. 8

   Lubricate O-rings

   Lubricate the O-rings on the new solenoid valve with clean transmission/hydraulic fluid.

9. 9

   Install new solenoid

   Insert the new solenoid valve into the port and secure it with the flange and retaining screws. Tighten the screws to the OEM specified torque.

10. 10

    Reconnect wiring

    Reconnect the electrical connector.

11. 11

    Clear fault codes

    Reconnect the battery, start the tractor, and use the diagnostic interface (e.g., Wintest or the tractor's dashboard menu) to clear the fault codes.

12. 12

    Test drive

    Test drive the tractor, shifting through all ranges to confirm Range 4 engages smoothly and the code does not return.