Massey Ferguson 14.X.0A – TRANS1: Brake Pressure Sensor High Volts Dyna 6

The controller is receiving a voltage signal from the high-pressure brake system sensor (often the trailer air brake or ParkLock pressure sensor) that exceeds the normal operating range (typically > 5V). This usually indicates a short to power in the signal wire, an open ground wire causing the signal to float high, or an internally shorted sensor.

• 7714
• 7715
• 7715S
• 7716
• 7716S
• 7718
• 7718S
• 7719
• 7720
• 7720S
• 7722
• 7722S
• 7724
• 7724S
• 7726
• 7726S
• Tier 4 (2015-2021)
• 5709 S
• 5710 S
• 5711 S
• 5712 S
• 5713 S
• 6713 S
• 6714 S
• 6715 S
• 6716 S
• 6718 S
• 7715 S
• 7716 S
• 7718 S
• 7720 S
• 7722 S
• 7724 S
• 7726 S
• 6400 series
• 7400 series
• 7600 series
• 7615
• 8600 series

1. 1

   Visually inspect the air brake circuit / trailer brake pressure sensor wiring harness and connector for corrosion, moisture, or backed-out pins.

2. 2

   Use a multimeter to verify continuity on the sensor's ground circuit back to the TRANS1 module (an open ground will cause the sensor signal to read high voltage).

3. 3

   Disconnect the sensor and turn the key ON. Measure the signal wire voltage. If it reads 5V or 12V with the sensor unplugged, the wiring harness is shorted to a power source.

4. 4

   If the wiring tests good (proper 5V reference, good ground, and 0V on the signal wire when unplugged), the sensor itself has likely failed internally and is bridging the 5V reference to the signal output.

1. 1

   Depressurize the System

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

2. 2

   Disconnect the Sensor

   Unplug the electrical connector from the brake pressure sensor.

3. 3

   Remove the Sensor

   Unthread the faulty pressure sensor from the transmission/brake valve block.

4. 4

   Install the New Sensor

   Thread the new OEM sensor into the port. Do not overtighten, as this can damage the threads or the sensor body.

5. 5

   Reconnect Wiring

   Plug the electrical connector back in, ensuring the weather seal is intact and the locking tab clicks into place.

6. 6

   Clear Codes & Test

   Turn the ignition ON. Use the tractor's dashboard diagnostic menu or the AGCO Electronic Diagnostic Tool (EDT) to clear the 14.X.0A fault code. Start the tractor, build up brake pressure, and verify the code does not return.