Massey Ferguson 13.X.0C – TRANS1: Hydraulic Trailer Brake Solenoid Issue Dyna VT (TRANS1) - Short circuit to ground

Issue with component X39 (Trailer Braking Safety Solenoid Valve). The "0C" suffix designates the failure mode as a Short circuit to ground.

• 7714
• 7715
• 7715S
• 7716
• 7716S
• 7718
• 7718S
• 7719
• 7720
• 7720S
• 7722
• 7722S
• 7724
• 7724S
• 7726
• 7726S
• Tier 4 (2015-2021)
• 6614
• 6615
• 6616
• 7614
• 7615
• 7616
• 7618
• 7619
• 7620
• 7622
• 7624
• 7626
• 8670
• 8690

1. 1

   Visual Inspection: Locate the X39 trailer braking safety solenoid valve on the rear transmission/hydraulic valve block. Inspect the wiring harness leading to the solenoid for chafing, melted insulation, or pinch points against the tractor chassis that could cause a direct short to ground.

2. 2

   Harness Testing: Disconnect the electrical connector at the X39 solenoid. Use a multimeter to check for continuity between the power supply wire in the harness and the tractor chassis (ground). If there is continuity, the wiring harness is shorted and must be repaired.

3. 3

   Coil Resistance Test: If the harness tests fine, measure the internal resistance of the X39 solenoid coil itself. A reading of near-zero ohms indicates the solenoid coil has failed and shorted internally.

1. 1

   Park and relieve pressure

   Park the tractor on a level surface, engage the parking brake, and turn off the engine. Relieve any residual hydraulic pressure in the system.

2. 2

   Locate solenoid

   Locate the X39 Trailer Braking Safety Solenoid Valve on the transmission hydraulic block.

3. 3

   Disconnect harness

   Disconnect the electrical harness connector from the solenoid.

4. 4

   Repair wiring

   If the diagnostic checks pointed to a wiring issue, repair the chafed/shorted section of the harness and wrap it in protective loom.

5. 5

   Remove retaining nut

   If the solenoid coil is internally shorted, remove the retaining nut holding the coil to the valve stem.

6. 6

   Remove old coil

   Slide the old solenoid coil off. (Note: If the valve cartridge itself is damaged or leaking, you may need to unthread the entire valve cartridge from the block. Have a catch pan ready for hydraulic fluid).

7. 7

   Install new coil/valve

   Install the new OEM solenoid coil/valve and tighten to the manufacturer's specified torque.

8. 8

   Reconnect harness

   Reconnect the electrical harness.

9. 9

   Clear fault code

   Power on the tractor and use the diagnostic terminal to clear the 13.X.0C fault code from the TRANS1 module.

10. 10

    Test operation

    Test the hydraulic trailer brake remotes to ensure proper pressure and operation.