Massey Ferguson 04.03.9C – TRANS2: Transmission Input Shaft Speed Sensor Open Circuit

The controller is not detecting a complete electrical path to the input shaft speed sensor. An "open circuit" typically points to a disconnected plug, a severed or broken wire in the harness, or an internal failure (breakage) within the sensor itself.

• 7724S
• 5712SL
• 7722
• 7722S
• 5713SL
• 7720S
• 7716
• 7718
• T4
• 7715
• 5710SL
• 7726
• 7726S
• 5711SL
• 7718S
• 7719
• 7714
• 7716S
• 7720
• Tier 4 (2015-2021)
• 7715S
• 7724
• 5608
• 5609
• 5610
• 5611
• 5612
• 5613
• 6400 Series
• 6600 Series
• 6700 Series
• 7600 Series

1. 1

   Visual Inspection: Locate the sensor and inspect the wiring harness for obvious signs of damage, rubbing, or severed wires.

2. 2

   Connector Check: Ensure the electrical connector is fully seated and free of dirt, moisture, or corrosion.

3. 3

   Continuity Test: Use a multimeter to check the wiring harness between the TRANS2 controller and the sensor plug for continuity. If the wiring is intact, test the sensor itself for an internal open circuit.

4. 4

   Mechanical Inspection: If readings are erratic or the sensor tests fine electrically, verify the sensor gap and inspect the internal tone ring for damage.

1. 1

   Power Down

   Disconnect the tractor's battery before starting any electrical work.

2. 2

   Locate the Sensor

   Find the transmission input shaft speed sensor on the transmission housing. Note: Access can be tight depending on the specific tractor model.

3. 3

   Clean the Area

   Thoroughly clean the mounting area around the sensor to prevent dirt, dust, or debris from falling into the transmission housing when the sensor is removed.

4. 4

   Remove the Sensor

   Unplug the electrical connector, remove the retaining hardware, and pull the faulty sensor out of the housing.

5. 5

   Install the New Sensor

   Insert the replacement sensor. Ensure it is positioned correctly relative to the tone ring, as an improper gap will result in erratic readings or calibration faults.

6. 6

   Reconnect

   Plug the wiring harness back into the sensor and reconnect the battery.

7. 7

   Clear Codes

   Use a specialized diagnostic tool to clear the 04.03.9C DTC from the TRANS2 module and test drive the tractor to ensure the transmission shifts smoothly and the code does not return.