Massey Ferguson 14.02.0A – TRANS1: Brake Pressure Sensor High Volts Dyna 6 (TRANS1)

The transmission control module is receiving a voltage signal from the brake pressure sensor that exceeds the normal operating range (typically >5V or near the reference voltage limit). A "High Volts" condition usually points to an electrical fault such as a short circuit to power, an open ground circuit (which causes the signal voltage to float high), 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)
• 5709
• 5710
• 5711
• 5712
• 5713
• 6713
• 6714
• 6715
• 6716
• 6718
• 7614
• 7615
• 7616
• 7618
• 7619
• 7620
• 7622
• 7624
• 7626

1. 1

   Visually inspect the brake pressure sensor (X21 for ParkLock or X26 for pneumatic brakes) and its connector for water ingress, corrosion, or pushed-out pins.

2. 2

   Test the ground wire at the sensor connector (an open ground is the most common cause of a High Volts code because it prevents the sensor from pulling the reference voltage down).

3. 3

   Check the signal wire between the sensor and the TRANS1 module for a short to power (e.g., rubbing against a 12V source).

4. 4

   Verify the sensor is receiving the correct 5V reference supply from the controller.

5. 5

   If the wiring harness tests perfectly (good ground, good 5V reference, no shorts on the signal wire), conclude the sensor has failed internally and must be replaced.

1. 1

   Power Down

   Turn off the tractor and disconnect the battery to prevent electrical spikes during repair.

2. 2

   Depressurize

   Pump the brake pedals several times to relieve any residual hydraulic or pneumatic pressure in the braking system before removing the sensor.

3. 3

   Remove Sensor

   Disconnect the wiring harness from the brake pressure sensor. Use a wrench to carefully unthread the sensor from the brake valve block or ParkLock hydraulic block.

4. 4

   Install New Sensor

   Thread the new OEM sensor into the port. Tighten to the torque specification outlined in the specific model's workshop manual (do not overtighten, as this can damage the sensor diaphragm).

5. 5

   Reconnect

   Plug the wiring harness back into the sensor, ensuring the locking tab clicks into place.

6. 6

   Clear Codes

   Reconnect the battery. Use the AGCO Electronic Diagnostic Tool (EDT) or the tractor's onboard dashboard diagnostic menu to clear the 14.02.0A fault code.

7. 7

   Test

   Start the tractor, actuate the brakes, and verify that the fault code does not return and that brake pressures read normally on the diagnostic display.