Massey Ferguson 04.02.07 – TRANS: Transmission High Pressure Sensor 2 Signal Voltage Issue

The transmission control system is receiving an erratic, out-of-range, or missing electrical voltage signal from the second high-pressure sensor on the transmission's hydraulic circuit. This sensor monitors the instantaneous hydrostatic/hydraulic oil pressure to ensure the transmission shifts correctly and maintains proper line pressure.

• 7714
• 7715
• 7715S
• 7716
• 7716S
• 7718
• 7718S
• 7719
• 7720
• 7720S
• 7722
• 7722S
• 7724
• 7724S
• 7726
• 7726S
• Tier 4 (2015-2021)
• 7700 Series
• 7700S Series

1. 1

   Locate Transmission High Pressure Sensor 2 (often designated as sensor X34 or X9) on the transmission housing/valve block and visually inspect the connector for dirt, moisture, corrosion, or backed-out pins.

2. 2

   Check the wiring harness between the sensor and the Autotronic TCU for chafed wires causing a short to ground, a short to +12V, or an open circuit.

3. 3

   Using a multimeter, verify that the sensor is receiving its proper reference voltage from the ECU (typically 5V or 8.5V depending on the exact sensor generation).

4. 4

   Read the live voltage output of the sensor using a diagnostic tool (like AGCO EDT or EDIA-PRO). If the voltage is stuck at 0V or 5V regardless of engine RPM and transmission load, the sensor has failed internally.

1. 1

   Preparation

   Park the tractor on a level surface, engage the ParkLock or handbrake, and turn off the engine. Relieve any residual hydraulic pressure if required by the service manual.

2. 2

   Removal

   Disconnect the electrical harness from High Pressure Sensor 2. Unscrew the sensor from the transmission housing (have a rag ready to catch minor hydraulic fluid loss).

3. 3

   Installation

   Thread the new OEM pressure sensor into the port and tighten to the manufacturer's specified torque. Reconnect the electrical harness.

4. 4

   MANDATORY CALIBRATION

   A Transmission Calibration must be carried out systematically after changing the transmission high pressure sensor. Prerequisites: Hand brake applied (or ParkLock engaged), Power Control lever in the neutral position, and the High/Low (Hare/Tortoise) range in neutral. Initiate the calibration sequence via the tractor's terminal/dash and follow the on-screen prompts until the transmission ratios validate.