Case IH NH1002 – EDC (Electronic Draft Control) / Hitch control module: Ground Speed Radar Disconnected

The fault code NH1002 indicates an open circuit or loss of signal from the ground speed radar sensor, meaning the radar is disconnected. The tractor's control unit has lost communication with the sensor, which measures true ground speed by emitting radar waves and analyzing reflected signals. This prevents proper operation of systems that rely on accurate radar input, such as slip control, automatic draft adjustments, and area calculations.

• Magnum 235
• Magnum 260
• Magnum 290
• Magnum 315
• Magnum 340
• Magnum 370
• Steiger 335
• Steiger 385
• Steiger 550
• MXM120
• MXM130
• MXM140
• MXM155
• MXM175
• MXM190
• MXU100
• MXU110
• MXU115
• MXU125
• MXU135
• Puma
• Farmall 85U
• Farmall 95U
• Farmall 105U
• JX70U
• JX80U
• JX90U
• JX100U
• JX1070U
• JX1080U
• JX1090U
• JX1100U

1. 1

   Inspect the wiring harness and connectors leading to the radar sensor for chafing, breaks, or corrosion, paying close attention to moisture intrusion at the sensor connector.

2. 2

   Verify the sensor is receiving correct voltage and has a solid ground connection using a multimeter.

3. 3

   Unplug the radar sensor as a temporary diagnostic step; if the speed reading returns on the display (defaulting to the transmission output speed sensor), the radar sensor or its dedicated wiring is likely at fault.

4. 4

   Check for other active or stored fault codes related to sensor supply voltage or CAN bus communication errors, which could point to a broader electrical issue.

1. 1

   Safety First

   Before beginning any work, ensure the tractor is on a level surface, the parking brake is engaged, and the engine is turned off. Disconnect the battery to prevent electrical shorts.

2. 2

   Locate the Radar Sensor

   The ground speed radar is typically mounted underneath the tractor chassis, pointing towards the ground.

3. 3

   Disconnect and Inspect

   Disconnect the electrical connector from the sensor. Inspect the pins on both the sensor and the harness connector for corrosion, moisture, or damage. Clean with an appropriate electrical contact cleaner if necessary.

4. 4

   Test the Circuit

   If you have access to a wiring diagram or pinout information, test for power, ground, and signal continuity in the harness running from the control module to the sensor connector. Wiggling the wires while testing with an ohmmeter can help identify intermittent breaks inside the insulation.

5. 5

   Replace the Sensor

   If the wiring is confirmed to be intact and the sensor is suspected to be faulty, remove the mounting bolts and replace the radar unit.

6. 6

   Reconnect and Re-test

   Securely mount the new sensor and reconnect the electrical harness. Reconnect the battery.

7. 7

   Clear Fault Codes

   Start the tractor and use a diagnostic service tool to clear the NH1002 fault code.

8. 8

   Calibrate and Verify

   Operate the tractor to ensure the ground speed is reading correctly on the display. Some systems may require a calibration procedure after replacing the sensor, which can sometimes be found in the operator's manual.