New Holland NH 1049 – XCM, VCM, or TRANS: Wheel speed sensor open circuit

The control module is not receiving a valid electrical signal from the wheel speed sensor (often functioning as the transmission output speed sensor). The "open circuit" designation means there is a break in the electrical path, which is typically caused by a disconnected plug, a severed wiring harness, or an internal failure of the sensor itself.

• T5 series
• T7 series
• TM series
• TG series
• TG215
• TG285
• B110B
• LB110
• B115
• LB115
• NH 1049 self-propelled bale wagons

1. 1

   Inspect Connectors: Check the output speed sensor connector (e.g., connector C038) and the central controller (XCM) connector (e.g., C537). Ensure they are fully seated, not damaged, and that the pins are tight and in the correct positions.

2. 2

   Wiring Continuity: Test the wiring harness between the sensor and the controller with a multimeter to rule out a broken wire (open circuit) or a short to ground/power.

3. 3

   Sensor Mounting: Check if the output speed sensor is loose in the transmission housing. A loose sensor increases the air gap and drops the signal.

4. 4

   Mechanical Inspection: If the tractor is not moving at all, there may be a mechanical fault within the transmission or rear axle.

5. 5

   Tone Ring / Pickup Disc: Remove the speed sensor and look inside the transmission housing to check the speed pickup disc (tone wheel). Ensure it is not distorted, bent, or damaged.

1. 1

   Locate the Sensor

   Find the wheel speed / transmission output speed sensor mounted on the transmission housing or axle housing.

2. 2

   Disconnect and Inspect

   Unplug the electrical harness from the sensor. Clean the connector contacts and check for moisture, corrosion, or pushed-back pins. Repair the harness if necessary.

3. 3

   Remove the Sensor

   If the wiring is intact, remove the retaining bolt securing the sensor to the housing and pull the sensor out.

4. 4

   Inspect the Cavity

   Look into the mounting hole to verify the internal speed pickup disc is intact and free of debris.

5. 5

   Install the New Sensor

   Insert the replacement wheel speed sensor into the housing. Tighten the retaining bolt to the OEM torque specification to ensure the correct air gap.

6. 6

   Reconnect

   Plug the electrical harness back into the sensor securely.

7. 7

   Clear Codes and Test

   Use the tractor's diagnostic menu (H-routines) or an Electronic Service Tool (EST) to clear the F49 / NH 1049 error code. Test drive the tractor to confirm the speedometer works, the transmission shifts correctly, and the code does not return.