Massey Ferguson T4173 – Transmission Control Unit (TCU): X19 - Transmission hydraulic oil temperature sensor Signal error

The transmission controller is receiving an erratic, out-of-range, or missing electrical signal from the X19 transmission hydraulic oil temperature sensor.

• 7622
• Interim Tier 4 (2012-2015)
• 7614
• 7615
• 7620
• 7616
• 7618
• 7619
• 7626
• 7624
• 8650
• 8660
• 8670
• 8680
• 8690

1. 1

   Verify transmission/hydraulic oil level and condition (check for burnt smell, milky appearance, or metal filings)

2. 2

   Inspect the wiring harness and connector at the X19 temperature sensor for chafing, breaks, dirt, or corrosion

3. 3

   Test the sensor resistance with a multimeter and compare the reading against the ambient temperature to identify shorts or impossible values

4. 4

   Check for concurrent overheating codes (e.g., T4153) to rule out actual transmission overheating

1. 1

   Preparation

   Park the tractor on a level surface, engage the parking brake, and turn off the engine. Allow the transmission fluid to cool completely to avoid burns.

2. 2

   Locate the Sensor

   Locate the X19 transmission hydraulic oil temperature sensor, typically threaded into the lower section or side of the transmission casing.

3. 3

   Drain or Plug

   Depending on the sensor's exact location relative to the fluid level, you may need to drain the transmission oil into a clean pan. Alternatively, have the new sensor ready to thread in immediately to minimize fluid loss.

4. 4

   Remove the Faulty Sensor

   Disconnect the electrical connector. Use a deep socket or wrench to carefully unscrew the X19 sensor from the transmission housing.

5. 5

   Install the New Sensor

   Apply a medium-strength thread sealant (such as Loctite 242, as recommended by Massey Ferguson manuals) to the threads of the new sensor if it does not come pre-coated. Thread it in by hand to prevent cross-threading, then tighten to the OEM torque specification.

6. 6

   Reconnect and Refill

   Reconnect the electrical harness. Top off the transmission fluid using the approved AGCO/Massey Ferguson lubricant (e.g., AGCO V-TRANS PLUS).

7. 7

   Clear Codes

   Turn the key on, clear the stored fault codes from the transmission controller, and test drive the tractor to ensure the code does not return and the temperature reads accurately.