Case IH 1004 - UCM – UCM: Wheel speed sensor - signal too high

This fault code indicates that the control module is receiving a voltage signal from the wheel speed sensor (or output wheel speed sensor) that exceeds the expected maximum threshold. This typically points to a short to power in the sensor circuit or an internal failure within the sensor itself.

• VESTRUM CVX
• Case IH Puma Series (125, 140, 165, 180, 195, 210, 225)
• Case IH Magnum Series (MX210, MX230, MX255, MX285, 7100, 7200, 235-340)
• Case IH Steiger Series

1. 1

   Inspect the wheel speed sensor and its wiring harness for physical damage, rubbing, or pinched wires.

2. 2

   Use a multimeter to check the sensor's signal wire for a short to a power source (e.g., a 5V or 12V reference wire).

3. 3

   Disconnect the sensor and inspect the pins for corrosion, moisture, or bent terminals.

4. 4

   Verify that the sensor is receiving the correct reference voltage (typically 5V) and has a solid ground connection.

1. 1

   Power Down

   Turn off the machine and disconnect the battery to prevent electrical spikes.

2. 2

   Locate the Sensor

   Locate the wheel speed sensor (often mounted on the transmission housing, final drive, or wheel hub depending on the specific model).

3. 3

   Wiring Repair (If Applicable)

   If the diagnostic checks revealed a short to power in the wiring harness, repair the damaged section of the wire and secure it with a wire guard to prevent future chafing.

4. 4

   Replace the Sensor

   If the wiring is intact, the sensor itself has likely failed internally. Disconnect the 3-pin plug, unthread/remove the old sensor, and install the new OEM wheel speed sensor.

5. 5

   Reassemble and Clear Codes

   Reconnect the battery. Use a compatible diagnostic tool (such as the Case IH EST or Jaltest diagnostic software) to clear the 1004 fault code from the UCM/EDC.

6. 6

   Test Drive

   Operate the tractor to ensure the wheel speed registers correctly on the dash/monitor and that the fault code does not return.