Massey Ferguson 14.02.05 – TRANS1: High Pressure Brake System Pressure Too High DYNA 6 (TRANS1)

The system has detected pressure in the high-pressure braking circuit (often associated with the pneumatic trailer brakes or the ParkLock system) that exceeds the maximum safe operating threshold. This can be caused by a genuine over-pressurization event (such as a blocked line or faulty regulator) or, more commonly, a failed brake pressure sensor sending an out-of-range high voltage signal to the controller.

• 7714
• 7715
• 7715S
• 7716
• 7716S
• 7718
• 7718S
• 7719
• 7720
• 7720S
• 7722
• 7722S
• 7724
• 7724S
• 7726
• 7726S
• Tier 4 (2015-2021)
• 5600 Series
• 5700SL Series
• 6400 Series
• 6465
• 6475
• 6480
• 7400 Series
• 7465
• 7475
• 7480
• 7600 Series
• 7614
• 7615
• 7616
• 7618
• 7620
• 7622
• 7624
• 7700 Series
• 8600 Series
• 8650
• 8660
• 8670
• 8680
• 8690

1. 1

   Verify actual pressure with a mechanical pressure gauge on the pneumatic/hydraulic brake test ports to determine if the system is genuinely over-pressurizing

2. 2

   Inspect implement connections (if a trailer is attached) and check the condition of the air connection couplers between the tractor and the implement for blockages

3. 3

   Inspect the Air Supply / Trailer Brake Pressure Sensor and its wiring harness for chafing, pinched wires, or corrosion at the connector that could cause a short circuit to power

4. 4

   Check the transmission and brake system fuses in the main and secondary fuse boxes to ensure they are intact

1. 1

   Isolate Power

   Turn off the tractor and engage the battery isolator switch to prevent electrical shorts while working on the transmission/brake sensors.

2. 2

   Access the Sensor

   Locate the high-pressure brake sensor, typically mounted on the air supply tank or the main trailer brake valve block.

3. 3

   Clean and Test the Connection

   Disconnect the sensor. Clean the contacts with electrical contact cleaner. If the wiring is damaged, splice in a new connector pigtail.

4. 4

   Replace the Sensor

   If the wiring is sound but the code persists (or if the sensor tests out of range with a multimeter), unthread the faulty pressure sensor and install the replacement part.

5. 5

   Bleed the System

   If the repair required opening hydraulic brake lines (rather than just the pneumatic side), you must perform the specific high-pressure braking system bleeding procedure for Dyna-6 transmissions as outlined in the workshop manual.

6. 6

   Clear Codes

   Reconnect the battery. Use a diagnostic tool or the tractor's onboard dashboard menu to clear the stored 14.02.05 fault code.

7. 7

   Test

   Start the tractor, allow the air/hydraulic pressure to build, and test the brake pedals and trailer brake actuation to ensure the code does not return.