Case IH 3003 – Engine Controller (Engine ECU / EDC): Foot Throttle Sensor - Signal Below Range Min

This fault code indicates that the voltage signal returning from the foot throttle position sensor (potentiometer) is lower than the minimum acceptable threshold programmed into the controller. This typically means the signal voltage has dropped near 0V, which points to an open circuit, a short to ground in the sensor wiring, or a complete internal failure of the sensor itself.

• Farmall
• Steiger T4B
• Magnum Series
• Puma Series
• Farmall Series
• Steiger / Quadtrac Series

1. 1

   Inspect the foot throttle pedal assembly inside the cab for debris blocking the pedal or damaged/disconnected mechanical linkage.

2. 2

   Inspect the wiring harness from the foot throttle sensor to the Engine ECU for chafed wires, pinched harnesses, or melted insulation causing a short to ground.

3. 3

   Disconnect the sensor and inspect the pins for corrosion, moisture, or pushed-back terminals.

4. 4

   Check for the 5V reference signal and a good ground at the sensor connector with the key ON and engine OFF.

5. 5

   Test the signal wire continuity back to the ECU to rule out an open circuit.

6. 6

   If the wiring is intact and the reference voltage is correct, but the signal output remains below the minimum range when the pedal is depressed, the sensor itself has failed.

1. 1

   Power Down

   Turn off the ignition and disconnect the battery master switch to prevent electrical spikes.

2. 2

   Locate the Sensor

   Locate the foot throttle potentiometer, which is mounted directly to the foot pedal assembly on the right side of the cab floorboard.

3. 3

   Disconnect

   Unplug the electrical connector (typically a Metri-Pack or similar multi-pin connector) from the sensor.

4. 4

   Remove the Sensor

   Remove the retaining screws/bolts holding the sensor to the pedal bracket. Carefully slide the old sensor off the linkage shaft.

5. 5

   Install the New Sensor

   Align the new potentiometer with the pedal shaft keyway and secure it with the mounting hardware.

6. 6

   Reconnect

   Plug the electrical connector back into the sensor, ensuring the locking tab clicks into place.

7. 7

   Test and Clear Codes

   Reconnect the battery and turn the key to the ON position. Use a diagnostic scan tool (such as the Case IH EST or Jaltest) to clear the inactive 3003 fault code. Depress the pedal to ensure the voltage sweeps smoothly across the operating range without dropping out. (Note: Some models may require a brief throttle calibration routine via the instrument cluster or diagnostic tool to learn the new minimum/maximum pedal limits).