Massey Ferguson P51 – TRANS1: Park Brake Release Solenoid Open Circuit Dyna VT (TRANS1)

The transmission control system has detected an open circuit on the electrical line that operates the park brake release solenoid, indicating a break in the wiring, a disconnected or corroded plug, or a failed internal electromagnetic coil.

• 7614
• 7615
• 7616
• 7618
• 7619
• 7620
• 7622
• 7624
• 7626
• Interim Tier 4 (2012-2015)
• 6614
• 6615
• 6616
• 6S.135
• 6S.145
• 6S.155
• 6S.165
• 6S.180
• 6713 S
• 6714 S
• 6715 S
• 6716 S
• 6718 S
• 7715
• 7716
• 7718
• 7719
• 7720
• 7722
• 7724
• 7726
• 7S.145
• 8650
• 8660
• 8670
• 8680
• 8690
• 8727 S
• 8730 S
• 8732 S
• 8735 S
• 8737 S
• 8740 S

1. 1

   Visual Inspection: Locate the Park Brake Release Solenoid on the transmission valve block. Inspect the wiring harness leading to the solenoid for any obvious physical damage, chafing, or severed wires.

2. 2

   Connector Check: Disconnect the plug at the solenoid. Check for pushed-out pins, moisture ingress, or corrosion. Reconnect securely to ensure it wasn't simply a loose connection.

3. 3

   Coil Resistance Test: Using a multimeter, measure the resistance across the pins of the solenoid itself. If the multimeter reads 'OL' (Open Loop) or infinite resistance, the internal coil is broken, and the solenoid must be replaced.

4. 4

   Harness Continuity Test: If the solenoid tests within normal resistance specifications, disconnect the harness at the TRANS1 controller and check for continuity between the controller pins and the solenoid connector. Repair any broken wires found in the harness.

1. 1

   Disconnect battery

   Turn off the tractor and disconnect the battery to prevent short circuits.

2. 2

   Locate solenoid

   Locate the Park Brake Release Solenoid on the Dyna VT transmission housing/valve block.

3. 3

   Disconnect harness

   Depress the locking tab and disconnect the electrical harness from the solenoid.

4. 4

   Clean area

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

5. 5

   Remove retaining hardware

   Remove the retaining nut or bolts holding the solenoid coil/cartridge in place.

6. 6

   Remove faulty solenoid

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

7. 7

   Lubricate O-rings

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

8. 8

   Install new solenoid

   Insert the new solenoid into the valve block and torque the retaining hardware to OEM specifications.

9. 9

   Reconnect harness

   Reconnect the electrical harness, ensuring it clicks into place.

10. 10

    Reconnect battery and clear code

    Reconnect the battery, start the tractor, and clear the P51 fault code using a diagnostic tool.

11. 11

    Test park brake

    Test the park brake engagement and release functions to verify the repair.