Massey Ferguson 13.X.0E – TRANS1: Hydraulic Trailer Brake Solenoid Issue

The controller detects an undetermined fault with the X39 trailer braking safety solenoid valve's circuit or operation, which often points to an intermittent connection, out-of-range resistance, or a mechanically sticking valve.

• 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
• 8480 Dyna VT
• 8670
• 8690

1. 1

   Inspect the electrical connector at the X39 solenoid valve on the transmission hydraulic control block for moisture, corrosion, or pushed-back pins.

2. 2

   Check the X42 inline connector (exterior transmission harness to solenoid valves) for communication loss or poor connections.

3. 3

   Measure the resistance of the X39 solenoid coil with a multimeter and compare it against a known good solenoid on the same block to check for degradation.

4. 4

   Perform a hydraulic pressure test at the trailer brake circuit to determine if the tractor is over- or under-pressurizing the brakes, indicating a mechanically stuck valve.

1. 1

   Safely park the tractor on level ground, engage the parking brake, and turn off the engine.

   Safely park the tractor on level ground, engage the parking brake, and turn off the engine.

2. 2

   Relieve all hydraulic pressure from the tractor's auxiliary and braking circuits.

   Relieve all hydraulic pressure from the tractor's auxiliary and braking circuits.

3. 3

   Locate the X39 Trailer braking safety solenoid valve on the Dyna VT transmission valve block.

   Locate the X39 Trailer braking safety solenoid valve on the Dyna VT transmission valve block.

4. 4

   Disconnect the wiring harness from the X39 solenoid. Clean the contacts with electrical contact cleaner if dirt or moisture is present.

   Disconnect the wiring harness from the X39 solenoid. Clean the contacts with electrical contact cleaner if dirt or moisture is present.

5. 5

   If the solenoid coil is faulty, remove the retaining nut at the end of the solenoid stem and slide the coil off. If the valve cartridge itself is sticking, unscrew the cartridge from the hydraulic block.

   If the solenoid coil is faulty, remove the retaining nut at the end of the solenoid stem and slide the coil off. If the valve cartridge itself is sticking, unscrew the cartridge from the hydraulic block.

6. 6

   Install the replacement X39 solenoid/valve cartridge and tighten to OEM torque specifications.

   Install the replacement X39 solenoid/valve cartridge and tighten to OEM torque specifications.

7. 7

   Reconnect the electrical harness, ensuring the locking tab clicks into place.

   Reconnect the electrical harness, ensuring the locking tab clicks into place.

8. 8

   Start the tractor, test the hydraulic trailer brake function, and use a diagnostic tool to clear the 13.X.0E code from the TRANS1 module.

   Start the tractor, test the hydraulic trailer brake function, and use a diagnostic tool to clear the 13.X.0E code from the TRANS1 module.