Massey Ferguson 4.X.99 – TRANS2: Issue With Powershift P Solenoid Supply Voltage

The transmission control system has detected an abnormal voltage condition (such as an open circuit, short to ground, or short to power) on the electrical supply circuit dedicated to the Powershift "P" Solenoid. This prevents the transmission from properly shifting or engaging the associated clutch pack.

• 5710SL
• 5711SL
• 5712SL
• 5713SL
• T4
• 7714
• 7715
• 7715S
• 7716
• 7716S
• 7718
• 7718S
• 7719
• 7720
• 7720S

1. 1

   Verify that the tractor's battery is fully charged and the alternator is outputting the correct system voltage, as low overall voltage can trigger supply faults.

2. 2

   Trace the wiring harness from the TRANS2 module to the transmission valve block. Look for chafed wires, melted insulation, or pinch points.

3. 3

   Disconnect the electrical connector at the Powershift P Solenoid. Inspect the pins for corrosion, pushed-back terminals, or moisture ingress (a common issue on exposed transmission blocks).

4. 4

   Using a multimeter, measure the resistance across the pins of the Powershift P Solenoid. If the circuit is open (infinite resistance) or shorted (near zero resistance), the solenoid coil has failed internally.

5. 5

   With the key ON, check the supply voltage at the harness connector to ensure the TRANS2 module is actually sending power to the solenoid.

1. 1

   Prep the Machine

   Park the tractor on a level surface, engage the parking brake, turn off the engine, and disconnect the negative battery cable.

2. 2

   Locate the Solenoid

   Locate the transmission control valve block on the side of the transmission housing. Identify the specific "P" solenoid (refer to the OEM service manual diagram for your specific Dyna transmission to ensure you do not pull the L or N solenoid by mistake).

3. 3

   Clean the Area

   Thoroughly clean the area around the valve block with brake cleaner and compressed air to prevent dirt from entering the hydraulic system.

4. 4

   Remove the Solenoid

   Disconnect the electrical harness. Remove the retaining nut, bolt, or snap-ring holding the solenoid coil and valve cartridge in place. Carefully pull the solenoid straight out.

5. 5

   Install the New Part

   Lubricate the O-rings on the new solenoid valve with clean transmission/hydraulic fluid. Carefully insert the new cartridge into the valve block, ensuring the O-rings do not pinch or roll.

6. 6

   Secure and Reconnect

   Tighten the retaining hardware to the OEM torque specification. Reconnect the electrical harness until it clicks securely.

7. 7

   Test

   Reconnect the battery. Use a diagnostic tool to clear the 04.02.99 fault code from the TRANS2 module. Start the tractor, check for hydraulic leaks, and test drive to verify that the powershift ranges engage smoothly.