Massey Ferguson 13.03.0C – TRANS1: Hydraulic Trailer Brake Solenoid Issue Dyna VT (TRANS1)

The control module has detected an electrical or functional anomaly (such as an open circuit, short circuit, or abnormal amperage draw) in the solenoid responsible for actuating the hydraulic trailer brakes.

• 7714
• 7715
• 7715S
• 7716
• 7716S
• 7718
• 7718S
• 7719
• 7720
• 7720S
• 7722
• 7722S
• 7724
• 7724S
• 7726
• 7726S
• Tier 4 (2015-2021)
• 6614
• 6615
• 6616
• 7615
• 7616
• 7618
• 7619
• 7620
• 7622
• 7624
• 7626
• 8S.205
• 8S.225
• 8S.245
• 8S.265

1. 1

   Visual Inspection: Locate the hydraulic trailer brake solenoid on the transmission hydraulic control block. Inspect the wiring harness and the connector for chafing, breaks, or corrosion.

2. 2

   Electrical Testing: Disconnect the solenoid and use a multimeter to measure the resistance across the solenoid coil pins. Compare the reading to OEM specifications to ensure the coil is not internally shorted or open.

3. 3

   Voltage/Signal Check: With the tractor running and the brake pedal depressed, check the harness side of the connector for proper voltage/signal from the TRANS1 module.

4. 4

   Hydraulic Pressure Check: Related codes (like 13.03.18) indicate that the system monitors pressure drops when the brake is applied. Ensure there are no severe hydraulic leaks or blocked filters in the transmission circuit that could cause the solenoid to fail to actuate the valve properly.

1. 1

   Preparation

   Park the tractor on a level surface, engage the parking brake, turn off the engine, and remove the key. Allow the transmission/hydraulic fluid to cool.

2. 2

   Relieve Pressure

   Actuate the brake pedals a few times to relieve any residual hydraulic pressure in the trailer braking circuit.

3. 3

   Access the Solenoid

   Locate the faulty trailer brake solenoid on the Dyna VT transmission valve block (usually accessed from the side or rear of the transmission housing).

4. 4

   Removal

   Disconnect the electrical harness connector from the solenoid. Remove the retaining nut or bolt at the end of the valve stem. Slide the electromagnetic coil (solenoid switch) off the hydraulic valve cartridge. (Note: If the mechanical valve cartridge itself is seized and needs replacement, you will need to unscrew it from the block. Have a catch pan ready for hydraulic fluid).

5. 5

   Installation

   Slide the new solenoid coil onto the valve stem and secure it with the retaining nut.

6. 6

   Reconnection

   Plug the electrical harness back into the new solenoid, ensuring the weather seal clicks into place.

7. 7

   Clear Codes

   Start the tractor, test the trailer brake remotes for proper operation, and use an AGCO diagnostic tool to clear the 13.03.0C code from the TRANS1 module.