Case IH 03 – EDC: Radar (Ground Speed) Greater Than Wheel Speed

The Electronic Draft Control (EDC) or Hitch Control module has detected a discrepancy where the radar-measured ground speed is higher than the wheel speed calculated from the wheel speed sensor. This indicates a discrepancy in speed measurement or sensor input, suggesting a potential issue with one of the speed sensors, the associated wiring, a defective speed pickup disc, or the alignment of the radar unit.

• MXM 120
• MXM 130
• MXM 140
• MXM 155
• MXM 175
• MXM 190
• JX70U
• JX80U
• JX90U
• JX100U
• JX1070U
• JX1080U
• JX1090U
• JX1100U
• MXU100
• MXU110
• MXU115
• MXU125
• MXU135
• Magnum 180
• Magnum 225
• Magnum 250
• Magnum 280
• Magnum 310
• Magnum 340
• Magnum 380

1. 1

   Inspect the electrical connectors for both the radar sensor and the wheel speed sensor to ensure they are securely connected, free of corrosion, and pins are correctly seated

2. 2

   Verify the instrument panel speed reading; an erratic or nonexistent speed reading points to a wheel speed sensor issue

3. 3

   Check the fuse that protects the radar and hitch control circuits

4. 4

   Visually inspect the radar unit to ensure it is correctly aligned and not obstructed by mud, debris, or damage

5. 5

   Examine the wiring harnesses leading to both the radar and wheel speed sensors for any signs of chafing, cuts, or corrosion

1. 1

   Address immediate issues

   Rectify any issues found during visual inspection, such as loose connectors, a blown fuse, or a misaligned radar. Clean corroded connectors and repair damaged wiring. Clear the fault codes and operate the tractor to see if the code returns.

2. 2

   Test the wheel speed sensor

   If the fault persists, measure the wheel speed sensor's resistance with a multimeter and compare it to specifications or a known good sensor. Check for an AC voltage signal from the sensor while rotating the wheel.

3. 3

   Test the radar sensor

   If the wheel speed sensor is functioning correctly, check for a +12 Volt supply at the radar connector. If power is present but the sensor is not functioning, the radar unit may be faulty.

4. 4

   Replace faulty sensor

   If the wheel speed sensor is faulty, disconnect its electrical connector, remove the mounting bolt, extract the sensor, and install the new one. If the radar sensor is faulty, disconnect its connector, remove mounting hardware, install the new unit ensuring correct alignment, and reconnect wiring.

5. 5

   Final verification

   After replacing any components, clear the fault codes and operate the tractor under normal conditions to confirm that the repair has been successful.