Case IH 05 – DIC / XCM: Wheel Speed Zero When Radar Indicates Ground Speed

The system reports that the wheel speed is zero, but the radar indicates that the machine is moving across the ground. This discrepancy suggests a potential issue with the data being received or processed by the system, triggering the fault code to alert the operator to a failure in the speed-sensing circuits.

• MXM
• TG
• Steiger 335
• Steiger 385
• Steiger 500
• Magnum 305
• Magnum MX255
• Magnum 7130
• Magnum 7250

1. 1

   Verify that ERROR CODE 5 is active or stored in the Digital Instrument Cluster and note any other active codes

2. 2

   Check the fuse supplying power to the radar unit (often Fuse 9)

3. 3

   Visually inspect the electrical connectors for both the wheel speed sensor and the radar unit for corrosion, bent or pushed-back pins, and moisture intrusion

4. 4

   Inspect the wiring harnesses leading to both sensors for visible damage, chafing, breaks, or short circuits to the chassis

5. 5

   Verify the correct voltage supply to the radar unit's connector with the key on

6. 6

   Isolate the faulty sensor by viewing live speed readings in the Pro series monitor (e.g., Pro 600, Pro 700) diagnostics, or by unplugging the radar unit to see if the controller defaults to the transmission speed sensor

1. 1

   Repair wiring and connectors

   If any issues were found during diagnostic checks, repair damaged wiring, replace blown fuses, and clean corroded connectors with electrical contact cleaner and dielectric grease.

2. 2

   Test wheel speed sensor

   Disconnect the transmission-mounted wheel speed sensor and measure its resistance. Expected resistance for Magnum models is 2925 to 3575 Ohms. If out of spec, replace the sensor. If within spec, check wiring continuity to the controller.

3. 3

   Test radar unit

   The radar unit is usually mounted under the front 'nose' of the tractor. Check the wiring to the radar's 4-pin connector (Pin A: Ground, Pin B: Signal, Pin C: 12V Power In, Pin D: 12V Power Out). If wiring is intact and receiving power but outputting no signal, the radar unit has failed.

4. 4

   Inspect speed pickup disc

   Inspect the mechanical speed pickup disc or tone ring that the wheel speed sensor reads for damage or debris buildup.

5. 5

   Replace faulty sensor

   Replace the wheel speed sensor or radar unit based on the testing results.

6. 6

   Clear codes and test

   Clear the error code from the system and test the tractor to ensure normal operation.