New Holland NH 2049 – Transmission Control Unit (TCU) or Chassis / ATC: Wheel speed sensor short or open

The control module has detected an electrical malfunction in the sensor's circuit, such as a broken wire (open circuit), a short to ground, or a short to a 12V power source, preventing the system from reading the tractor's wheel/transmission speed.

• TL100A
• TS100A
• TS110A
• TS115A
• TS120A
• TS125A
• TS130A
• TS135A
• T7.175
• T7.190
• T7.210
• T7.225
• T7.260
• T8 Series
• TM Series
• T6 Series

1. 1

   Crawl under the machine and check if the sensor is caked in mud or dirt. Clean the sensor and the surrounding area.

2. 2

   Inspect the wiring harness and connector for the sensor. Look for dust, moisture, corrosion, or broken wires causing an open circuit.

3. 3

   Remove the sensor and inspect the tip for physical damage or cracks caused by contact with internal transmission parts.

4. 4

   Verify that the internal toothed tone ring is clean and intact.

1. 1

   Locate the Sensor

   The wheel speed / transmission output speed sensor is typically mounted on the transmission housing or the rear axle housing.

2. 2

   Clear Access

   You may need to remove obstructing components to get a wrench on the sensor. In some models, removing the hydraulic filter is necessary to gain access.

3. 3

   Remove the Old Sensor

   Unplug the electrical connector and unscrew the sensor. Be prepared for it to be extremely tight.

4. 4

   Install the New Sensor

   Thread the new sensor into the housing. Ensure it is positioned correctly relative to the tone ring.

5. 5

   Reassembly

   Reinstall the hydraulic filter (if removed) and top off any lost hydraulic/transmission fluid. Reconnect the sensor's electrical harness.

6. 6

   Clear Codes and Test

   Use a compatible diagnostic code reader to clear the NH 2049 fault code from the ECU. Test drive the tractor to verify that the speedometer reads correctly and that the transmission can successfully shift through all gears.