Massey Ferguson T4146 – DYNA VT (TRANS): Pressure Is Not Seen To Drop When Turbo Clutch Solenoid Is Activated

Triggered when the transmission controller commands the turbo clutch solenoid valve to open, but the system does not detect the expected drop in hydraulic pressure. This typically indicates that the TK valve is jammed, the solenoid is mechanically locked/stuck closed, or there is an electrical fault keeping the valve externally energized.

• 7614
• 7615
• 7616
• 7618
• 7619
• 7620
• 7622
• 7624
• 7626
• Interim Tier 4 (2012-2015)
• MF 7614
• MF 7615
• MF 7616
• MF 7618
• MF 7619
• MF 7620
• MF 7622
• MF 7624
• MF 7626

1. 1

   Verify the transmission oil level and quality, and check if the transmission high-pressure filter is blocked (monitored by the S017 switch).

2. 2

   Test the wiring harness leading to the Y004 turbo-clutch solenoid for shorts to power or ground.

3. 3

   Inspect the Y004 solenoid to see if it is mechanically locked (ensure it hasn't been manually overridden by turning the hexagon socket head screw to the stop).

4. 4

   Check the high-pressure (PH) connection and connection T. If pressure remains at ~550 bar and does not drop, the TK valve may be jammed or the clutch valve (4V5) may be leaking.

1. 1

   Preparation

   Park the tractor on a level surface, engage the parking brake, turn off the engine, and allow the transmission fluid to cool. Relieve any residual hydraulic pressure in the system.

2. 2

   Locate the Valve

   Locate the transmission valve block. Identify the Y004 Turbo-clutch solenoid valve.

3. 3

   Inspect and Clean

   Clean the area around the valve block to prevent dirt from entering the transmission hydraulic circuit.

4. 4

   Remove the Solenoid

   Disconnect the electrical connector from the Y004 solenoid. Unbolt and carefully remove the solenoid valve from the block.

5. 5

   Inspect the Bore

   Check the valve bore for debris, metal shavings, or scoring that could have caused the TK valve to jam.

6. 6

   Install the New Valve

   Lubricate the O-rings on the new OEM solenoid valve with clean transmission fluid. Insert it into the valve block and torque the retaining bolts to the manufacturer's specification.

7. 7

   Reconnect and Clear Codes

   Reconnect the electrical harness. Use an AGCO Electronic Diagnostic Tool (EDT) or equivalent scanner to clear the T4146 fault code from the DYNA VT (TRANS) module.

8. 8

   Test Operation

   Start the tractor and test the transmission under load to ensure the turbo-clutch function operates smoothly and the high-pressure circuit drops pressure appropriately when the clutch is activated.