Massey Ferguson T152 – Transmission ECU (TRANS1) / Autotronic 5: Brake Pressure Sensor Open Circuit Dyna 6 (TRANS1)

The transmission controller has detected an open circuit, a loss of signal, or a physical disconnection from the brake pressure sensor located on the 50 km/h high-pressure braking unit.

• 7614
• 7615
• 7616
• 7618
• 7619
• 7620
• 7622
• 7624
• 7626
• Interim Tier 4 (2012-2015)
• MF 5400 Series
• MF 6400 Series
• MF 6700 S Series
• MF 7600 Series

1. 1

   Visually inspect the X495 brake pressure sensor on the 50 km/h high-pressure braking unit to see if it is unplugged or if the connector is loose.

2. 2

   Inspect the wiring harness between the X495 sensor and the Autotronic 5 (TRANS1) controller for chafing, breaks, or corrosion that would cause an open circuit.

3. 3

   Disconnect the sensor and check the connector pins for damage or moisture ingress.

4. 4

   Use a multimeter to verify continuity on the signal and ground wires back to the ECU.

5. 5

   Test the sensor itself for an internal open circuit if the wiring and continuity are intact.

1. 1

   Power Down

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

2. 2

   Access the Sensor

   Locate the high-pressure braking unit (typically near the master cylinder/transmission housing depending on the specific model) and identify the X495 brake pressure sensor.

3. 3

   Repair Wiring (If Applicable)

   If the diagnostic checks revealed a broken wire or damaged connector, splice in a new section of wire or replace the connector pigtail.

4. 4

   Replace the Sensor (If Applicable)

   If the wiring is good but the sensor has failed internally, unscrew the faulty X495 sensor from the braking unit. Install the new sensor and tighten it to the OEM torque specification.

5. 5

   Reconnect and Clear Codes

   Plug the sensor back into the harness, reconnect the battery, and use a diagnostic tool to clear the T152 fault code from the Autotronic 5 ECU.

6. 6

   Test Drive

   Start the tractor and test the brakes, ensuring the 50 km/h transport speed functions correctly and the code does not return.