New Holland TMF 35 – Instrumentation Controller (ICU): Slip Sensor (radar or wheel speed) is failed in the Instrumentation Controller

The controller is no longer receiving a valid signal from the ground speed radar or the wheel speed sensor, making it impossible for the tractor to calculate the wheel slip percentage accurately.

• T6010-T6090
• T6.140-T6.180
• T7030-T7070
• T7.170-T7.270
• T8040
• T8.300-T8.410
• TM115-TM190
• TS100A-TS135A
• 5640
• 6640
• 7740
• 8160
• 8670
• 8770
• 8970

1. 1

   Visually inspect the radar sensor (under cab/chassis) or wheel speed sensor (on transmission/axle). Ensure the radar lens is clean and unobstructed by heavy mud or debris.

2. 2

   Inspect the wiring harness leading to the sensor for chafing, cuts, or melted insulation.

3. 3

   Disconnect the sensor and check the connector pins for corrosion, moisture ingress, or loose terminals.

4. 4

   Verify mounting and alignment: for radar sensors, ensure the mounting bracket is not bent (incorrect angle causes signal failure); for wheel speed sensors, ensure it is fully seated to maintain the correct air gap.

5. 5

   Check for other active fault codes (such as TMF 32 - Ground Speed Signal failed) which might point to a broader harness or controller issue rather than the sensor itself.

1. 1

   Power Down

   Turn off the tractor and disconnect the battery to prevent electrical spikes to the Instrumentation Controller.

2. 2

   Locate the Sensor

   Identify whether your specific model uses a transmission-mounted wheel speed sensor or a chassis-mounted radar sensor for slip calculation.

3. 3

   Disconnect

   Unplug the electrical connector from the faulty sensor.

4. 4

   Remove

   For Radar: Unbolt the sensor from its mounting bracket. Keep the bracket in place to preserve the factory mounting angle. For Wheel Speed Sensor: Remove the retaining bolt and carefully pull the sensor straight out of the transmission/axle housing.

5. 5

   Install

   Fit the new sensor. If installing a radar sensor, ensure it is facing the correct direction and securely fastened. If installing a wheel speed sensor, lubricate the O-ring (if applicable) and seat it fully before tightening the retaining bolt.

6. 6

   Reconnect

   Plug the wiring harness back into the sensor, ensuring the locking tab clicks into place.

7. 7

   Test

   Reconnect the battery, start the tractor, and clear the stored fault codes. Perform a field test drive to verify that the slip percentage is now reading correctly on the cab display and that TMF 35 does not return.