Massey Ferguson 05.03.33 – TRANS1: Issue With 4wd Solenoid Circuit Dyna VT

A control error or electrical circuit malfunction (such as an open circuit, short to ground, or short to power) in the 4-wheel drive (4WD) solenoid valve circuit. When this fault is active, the transmission controller cannot properly command the 4WD solenoid, which directs the 17-bar hydraulic pressure required to operate the 4WD clutch assembly.

• 7714
• 7715
• 7715S
• 7716
• 7716S
• 7718
• 7718S
• 7719
• 7720
• 7720S
• 7722
• 7722S
• 7724
• 7724S
• 7726
• 7726S
• Tier 4 (2015-2021)
• 7614
• 7615
• 7616
• 7618
• 7619
• 7620
• 7622
• 7624
• 7626
• 8670
• 8690
• 6700S Series
• 7700 Series
• 8700 Series

1. 1

   Inspect the wiring harness between the TRANS1 controller and the 4WD solenoid valve (identified in OEM schematics as connector X5). Look for chafed wires, corrosion, or loose pins.

2. 2

   Use a multimeter to test the X5 circuit for continuity. Check for an open circuit, a short to ground, or a short to power.

3. 3

   Measure the resistance of the 4WD solenoid coil to ensure it is within the manufacturer's specifications. A reading of infinite resistance (open) or zero (shorted) means the coil has failed.

4. 4

   Verify that the 4WD engagement switch (connector X137) on the side pillar is sending the correct signal to the module, as a faulty switch can sometimes mimic or trigger engagement errors.

5. 5

   Ensure the transmission is producing the correct auxiliary pressure (approx. 17 to 18 bar) required for the 4WD clutch operation, measured at the designated test port.

1. 1

   Preparation

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

2. 2

   Locate the Solenoid

   Locate the 4WD solenoid valve (X5) on the transmission control block.

3. 3

   Disconnect

   Carefully unplug the electrical connector from the solenoid.

4. 4

   Removal

   If replacing just the coil: Remove the retaining nut at the end of the valve stem and slide the old coil off. If replacing the entire valve assembly: Clean the surrounding area to prevent dirt from entering the transmission. Unbolt the valve assembly from the control block.

5. 5

   Installation

   Install the new solenoid valve (ensure new O-rings are used and lubricated with clean transmission fluid) or slide on the new coil and tighten the retaining nut.

6. 6

   Reassembly

   Reconnect the X5 electrical connector and reconnect the battery.

7. 7

   Calibration/Clearing

   Turn the ignition on. Use a diagnostic tool or the tractor's onboard diagnostic screen to clear the 05.03.33 fault code.

8. 8

   Testing

   Start the tractor and test the 4WD engagement and disengagement to confirm the repair.