Case IH 12611 – Transmission Controller (TRANS) or Frame ECU: Front right wheel speed sensor - open circuit or shorted to battery

The fault indicates an electrical failure in the circuit for the front right wheel speed sensor. Open Circuit: There is a physical break in the wiring harness, a disconnected plug, or a failed internal sensor coil preventing the signal from reaching the controller. Shorted to Battery: The sensor's signal or ground wire is improperly making contact with a power source (battery voltage), causing the voltage reading to be too high. Without this signal, the machine may lose ground speed display on the A-post monitor and the transmission may restrict shifting.

• Magnum Series (e.g., MX255, 235–340 Series 4)
• Steiger Series (350–600 HP)
• Puma Series (e.g., Puma 125)
• JX-U Series (JX70U, JX80U, JX90U)
• 7230 Series
• 1225 Early Riser
• 1200PT
• 2140 Trailing Planters

1. 1

   Check the internal 5V reference voltage from the transmission controller (look for codes 2056 or 2057 indicating reference voltage is too high or low).

2. 2

   Inspect the front right wheel speed sensor connector (typically a 3-pin plug) for corrosion, moisture, or loose pins.

3. 3

   Inspect the wiring harness for chafing or pinched wires that could cause a short to battery power.

4. 4

   Check the gap between the wheel speed sensor and the associated toothed pole wheel (e.g., 60-tooth pole wheel) to ensure it is within tolerance.

5. 5

   If equipped, verify the radar input by test-driving the vehicle and checking the radar electrical connector on the left-hand side of the engine.

1. 1

   Disconnect Power

   Always disconnect the battery or power converter before servicing electrical components to prevent further shorts.

2. 2

   Locate the Sensor

   Locate the front right wheel speed sensor on the front axle hub assembly.

3. 3

   Test the Circuit

   Disconnect the sensor. Use a multimeter to check the chassis-side harness for continuity to the Transmission Controller (to rule out an open circuit) and check for voltage on the signal wire with the key on (to rule out a short to battery).

4. 4

   Remove the Sensor

   If the wiring is intact and the 5V reference is correct, the sensor itself has failed internally. Unbolt the sensor bracket or unthread the sensor from the housing.

5. 5

   Install the New Sensor

   Thread the new sensor into place (standard thread diameter is often 19.6mm with a 27mm thread length) and secure the wire guard/bracket.

6. 6

   Clear Codes and Test

   Reconnect the 3-pin plug, reconnect battery power, clear the fault codes from the Transmission Controller, and test drive the machine to ensure ground speed registers and the transmission shifts normally.