Massey Ferguson 05.01.33 – TRANS1: Issue With 4wd Solenoid Circuit Dyna VT

The transmission control system has detected an electrical anomaly—such as an open circuit, a short to ground, or a short to power—in the circuit responsible for actuating the 4-Wheel Drive (4WD) engagement solenoid.

• 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
• 8650
• 8660
• 8670
• 8680
• 8690
• 6600 Series
• 6700 S Series
• 7700 Series
• 7700 S Series
• 8700 Series
• 8700 S Series

1. 1

   Visually inspect the wiring harness from the TRANS1 module to the 4WD solenoid on the transmission hydraulic valve block for chafed wires, melted insulation, or pinch points.

2. 2

   Disconnect the electrical plug at the 4WD solenoid and inspect the pins for corrosion, moisture ingress, or pushed-out terminals.

3. 3

   Using a multimeter, measure the resistance across the pins of the 4WD solenoid coil (a healthy coil reads around 10 ohms; OL or zero indicates internal failure).

4. 4

   Check the wiring for continuity between the solenoid connector and the corresponding pins on the TRANS1 module to verify there is no short to ground or short to power in the harness.

1. 1

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

   Ensure the tractor is safely parked before beginning repairs.

2. 2

   Disconnect the negative battery terminal.

   This prevents electrical shorts during the repair process.

3. 3

   Locate the 4WD solenoid valve.

   It is located on the transmission hydraulic control block (usually on the side of the transmission housing; refer to the specific model's service manual for exact layout).

4. 4

   Thoroughly clean the area around the valve.

   This prevents dirt from entering the hydraulic system.

5. 5

   Disconnect the electrical wiring harness connector from the 4WD solenoid.

   Carefully unplug the connector from the solenoid.

6. 6

   Remove the faulty solenoid coil or electrovalve assembly.

   Depending on the exact part configuration, either remove the retaining nut at the end of the valve stem to slide the solenoid coil off, or unbolt the entire electrovalve assembly from the block.

7. 7

   Install the new solenoid coil or valve assembly.

   Torque any retaining nuts or bolts to OEM specifications.

8. 8

   Reconnect the electrical harness connector.

   Ensure it clicks securely into place.

9. 9

   Reconnect the battery.

   Restore power to the tractor.

10. 10

    Test the repair.

    Start the tractor, clear the stored DTC 05.01.33 using a diagnostic tool, and test the 4WD engagement/disengagement to confirm the repair.