John Deere 1387.03 – PTA: High Voltage On Transmission Oil Lube Pressure Sensor

The transmission control unit has detected a voltage in the transmission oil lube pressure sensor circuit that is higher than the normal operating range (FMI 03: Voltage Above Normal, or Shorted to High Source). This indicates a potential issue with the sensor itself, a short to a power source in the wiring, or a poor ground connection in the associated circuitry. This code is most commonly associated with 6R series tractors equipped with AutoPowr/IVT transmissions, particularly those manufactured between 2015 and 2021.

• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 9230
• 9330
• 9430
• 9530
• 9630
• 9360R
• 9410R
• 9460R
• 9510R
• 9560R

1. 1

   Inspect all wiring harnesses and connectors associated with the transmission lube oil pressure sensor for signs of damage, wear, corrosion, or disconnection.

2. 2

   Check the sensor circuit specifically for short circuits to a high voltage source or power.

3. 3

   Ensure the sensor is receiving the correct reference voltage from the PTA module and check for any issues in the power supply that might be causing a voltage spike.

4. 4

   Measure the sensor's voltage output with a multimeter to determine if the sensor is internally shorted and producing abnormally high voltage readings despite normal wiring.

1. 1

   Relieve Pressure

   Relieve hydraulic pressure by stopping the engine and operating all hydraulic control valves before disconnecting any lines or sensors.

2. 2

   Locate the Sensor

   Locate the Transmission Lube Oil Pressure Sensor on the transmission control valve housing.

3. 3

   Disconnect Electricals

   Carefully unplug the wiring harness connector from the sensor.

4. 4

   Remove the Sensor

   Remove the lube pressure sensor. (Note: On some 9-series models, a JDG669 Box End Adapter or similar specialty tool may be required for clearance).

5. 5

   Install the New Sensor

   Thread the new sensor into the housing. Tighten to the specified torque (refer to the specific machine's technical manual, as over-tightening can damage the valve housing).

6. 6

   Reassembly

   Reconnect the electrical harness.

7. 7

   Test

   Start the tractor, check for leaks around the new sensor, and verify that the PTA 001387.03 code can be cleared and does not return.