Massey Ferguson 14.02.07 – TRANS1: Brake Pressure Sensor Open Circuit

The transmission control module is detecting an incomplete electrical circuit (infinite resistance or zero voltage return) from the high-pressure brake system sensor. This is typically caused by a disconnected sensor plug, a severed wire in the harness, corroded connector pins, or an internal failure of the sensor itself.

• 7714
• 7715
• 7715S
• 7716
• 7716S
• 7718
• 7718S
• 7719
• 7720
• 7720S
• 7722
• 7722S
• 7724
• 7724S
• 7726
• 7726S
• Tier 4 (2015-2021)
• 5611
• 5612
• 5613
• 5709
• 5710
• 5711
• 5712
• 5713
• 6465
• 6475
• 6480
• 6485
• 6490
• 6495
• 6497
• 6499
• 6613
• 6614
• 6615
• 6616
• 6713
• 6714
• 6715
• 6716
• 6718
• 7614–7626
• 7714–7726

1. 1

   Locate the brake pressure sensor (often designated as X21 for ParkLock/brake pressure or X34/X35 depending on the exact hydraulic block). Inspect the wiring harness for chafing, rodent damage, or breaks.

2. 2

   Disconnect the sensor plug and check for water ingress, dirt, or corroded pins. Ensure the connector is fully seated and latched.

3. 3

   Using a multimeter, test the continuity of the signal, ground, and reference voltage wires from the sensor connector back to the TRANS1 module harness.

4. 4

   If the wiring is intact, perform a bench test on the sensor to check for an internal open circuit failure.

1. 1

   Depressurize the System

   Ensure the tractor is turned off, the parking brake is engaged, and the hydraulic/air braking system is safely depressurized before removing the sensor.

2. 2

   Disconnect the Battery

   Disconnect the negative battery terminal to protect the TRANS1 module from voltage spikes.

3. 3

   Remove the Faulty Sensor

   Unplug the electrical connector. Using the appropriate wrench, unthread the brake pressure sensor from the transmission/brake valve block. Have a rag ready to catch minor hydraulic fluid drips.

4. 4

   Install the New Sensor

   Thread the new OEM sensor into the port. If the sensor does not have a pre-applied thread sealant or O-ring, apply a medium-strength hydraulic thread sealant (e.g., Loctite 242) as specified by Massey Ferguson workshop manuals. Tighten to the specified torque.

5. 5

   Reconnect

   Plug the electrical connector back into the sensor until it clicks. Reconnect the battery.

6. 6

   Clear Codes and Test

   Turn the ignition on, clear the stored 14.00.07 fault code from the TRANS1 module, and start the tractor. Apply the brakes repeatedly to build pressure and verify the code does not return.