New Holland 2049 – TCM: Wheel Speed Sensor Error

The transmission controller has detected a loss of signal or an electrical fault (such as a short or open circuit) from one of the wheel speed sensors. The onboard computer relies on this signal for accurate ground speed data, which is crucial for proper functioning of the vehicle's speed monitoring system, automatic shifting, and traction control. A failure in this circuit can lead to noticeable transmission limitations, such as the tractor failing to shift into higher gears. For instance, a New Holland TS115A was reported to be limited to 13th gear when this fault was active.

• TL70A
• TL80A
• TL90A
• TL100A
• TS100A
• TS110A
• TS115A
• TS125A
• TS130A
• TS135A
• T6010
• T6020
• T6030
• T6040
• T6050
• T6060
• T6070
• T6080
• T6090
• T6.120
• T6.140
• T6.145
• T6.150
• T6.155
• T6.160
• T6.165
• T6.175
• T6.180
• T7.170
• T7.185
• T7.200
• T7.210
• TM110
• TM115
• TM120
• TM125
• TM130
• TM135
• TM140
• TM150
• TM155
• TM165
• TM175
• TM190

1. 1

   Visually inspect the wheel speed sensor and its wiring harness for any signs of physical damage, cuts, pinching, or abrasions. Pay close attention to the area around the sensor head and where the harness is routed near moving components.

2. 2

   Clean the sensor head and the surrounding toothed exciter ring to remove any accumulated mud, dirt, or metallic debris that could disrupt the magnetic pickup.

3. 3

   Disconnect the sensor's electrical connector and inspect the terminals for corrosion, moisture, or damage.

4. 4

   Measure resistance across the sensor pins with a multimeter. A typical passive sensor should read between 900 and 2,700 ohms. A reading of 'open circuit' (infinite resistance) or a dead short (near zero ohms) indicates a failed sensor. Compare the reading to the identical sensor on the opposite side of the axle.

5. 5

   Test AC voltage output by raising the wheel off the ground and rotating it by hand (at least half a revolution per second). A healthy passive sensor should generate a minimum of 0.25 Volts AC. No voltage output suggests a failed sensor or an issue with the toothed ring.

1. 1

   Park and secure

   Park the tractor on a level surface, engage the parking brake, chock the wheels, and disconnect the battery before beginning electrical work.

2. 2

   Locate the sensor

   Find the affected sensor. Location varies by model (e.g., right side of rear axle housing, in front of the axle on TS115A, or on the front axle for 4WD models). Access may require removing other components, such as a hydraulic filter. Always consult the service manual for the specific machine to confirm the correct location.

3. 3

   Remove the old sensor

   Disconnect the electrical connector. Unbolt and carefully remove the sensor from its housing. Note that the sensor can be very tight in its bore.

4. 4

   Inspect and clean

   Inspect the mounting bore and the toothed exciter ring for damage or debris. Clean the area thoroughly before installing the new sensor.

5. 5

   Install the new sensor

   Fit the new sensor into the housing. Ensure press-in types are fully seated, or tighten bolt-in types to the manufacturer's specified torque. If applicable, set the specific air gap to the exciter ring by gently pushing the sensor towards the ring until it makes light contact.

6. 6

   Reconnect and test

   Securely fasten the electrical connector, ensuring it clicks into place. Reconnect the battery.

7. 7

   Clear codes and verify

   Start the tractor and use the dashboard interface or a diagnostic tool to clear the fault code history. Operate the tractor, checking for the return of the fault code and verifying that normal operation (e.g., proper shifting, accurate speedometer reading) has been restored.