Massey Ferguson 13.03.15 – TRANS1: Park Brake Release Solenoid Open Circuit Dyna VT

The fault code indicates an Open Circuit in the electrical circuit for the Park Brake Release Solenoid. The transmission controller is sending a signal to energize the solenoid to release the park brake, but it is not detecting any electrical current flowing through the circuit. This usually means there is a broken wire, an unplugged connector, or the internal copper coil of the solenoid itself has broken (infinite resistance).

• 7714
• 7715
• 7715S
• 7716
• 7716S
• 7718
• 7718S
• 7719
• 7720
• 7720S
• 7722
• 7722S
• 7724
• 7724S
• 7726
• 7726S
• Tier 4 (2015-2021)
• 6600 / 6700 S Series (e.g., 6713 S, 6714 S, 6715 S, 6718 S Dyna-VT)
• 7600 / 7700 / 7700 S Series (e.g., 7715, 7718, 7720, 7724, 7726 Dyna-VT)
• 8600 Series (e.g., 8650, 8660, 8670, 8680, 8690)
• 8700 / 8700 S Series (e.g., 8727, 8730, 8737, 8740 Dyna-VT)
• Newer S Series (6S, 7S, 8S Dyna-VT models)

1. 1

   Visual Inspection: Locate the park brake release solenoid on the transmission hydraulic valve block. Check the electrical connector for corrosion, backed-out pins, or water ingress.

2. 2

   Wiring Harness Check: Trace the wiring harness from the solenoid back toward the TRANS1 module. Look for chafing, pinch points, or rodent damage, which are common causes of open circuits.

3. 3

   Coil Resistance Test: Disconnect the plug at the solenoid. Use a digital multimeter to measure the resistance (Ohms) across the two pins of the solenoid coil. An 'open circuit' will read as infinite resistance (O.L). If it reads open, the solenoid coil is dead and must be replaced.

4. 4

   Voltage Supply Test: With the connector unplugged, turn the key ON and command the park brake to release. Check for voltage (typically 12V) at the harness side of the connector to ensure the TRANS1 module is actually sending the signal.

1. 1

   Safety First

   Park the tractor on a flat, level surface. Chock the wheels securely, as you will be working on the park brake system. Disconnect the negative battery terminal.

2. 2

   Clean the Area

   Thoroughly clean the area around the transmission valve block to prevent dirt from entering the hydraulic system.

3. 3

   Disconnect the Solenoid

   Unplug the electrical connector from the park brake release solenoid.

4. 4

   Remove the Solenoid Coil/Valve

   Depending on the exact valve block revision, you may be able to remove just the retaining nut at the end of the valve stem and slide the electromagnetic coil off. If the valve is a single cartridge unit, unthread the entire solenoid cartridge from the valve block. (Have a catch pan ready for minor hydraulic fluid loss).

5. 5

   Install the New Part

   Slide the new coil onto the stem and torque the retaining nut, or thread the new cartridge valve into the block and torque to OEM specifications.

6. 6

   Reconnect and Test

   Reconnect the electrical plug. Reconnect the battery. Start the tractor, clear the stored fault codes via the dashboard or diagnostic tool, and test the park brake engagement and release. Check for hydraulic leaks.