Case IH t2 – Engine Control Unit (ECU) / Transmission Controller (EDC/TCU): Foot Throttle Position Sensor, Open Circuit Or Current Below Normal Range

The control module is detecting that the electrical signal from the foot throttle potentiometer has dropped below the minimum acceptable voltage threshold. This typically points to a broken wire, a disconnected plug, a failed sensor track (dead spot), or a short to ground.

• MXM
• MXM 120
• MXM 130
• MXM 140
• MXM 155
• MXM 175
• MXM 190
• Maxxum Series
• Puma Series
• Magnum Series
• Steiger Series

1. 1

   Verify the 5-volt reference supply and ground at the sensor connector, as low system voltage on the 5-volt sensor network is a frequent cause.

2. 2

   Inspect the wiring harness leading to the foot pedal for chafing, breaks, or moisture, and check the connector pins for corrosion, dirt buildup, or loose fitment.

3. 3

   Ensure the foot throttle pedal and linkage move freely without binding and that dirt or debris is not obstructing the sensor's range of motion.

4. 4

   Using a multimeter, perform a sensor sweep test to check the resistance/voltage sweep of the potentiometer while slowly pressing the pedal to see if the signal drops out.

1. 1

   Prep the Machine

   Park the tractor on a level surface, turn off the engine, engage the parking brake, and disconnect the battery to prevent electrical shorts.

2. 2

   Locate the Sensor

   Locate the foot throttle position sensor (potentiometer) mounted at the base of the foot throttle pedal assembly inside the cab.

3. 3

   Disconnect

   Carefully unplug the electrical harness connector from the sensor.

4. 4

   Remove

   Remove the retaining screws or bolts securing the sensor to the pedal linkage or mounting plate.

5. 5

   Install

   Install the new OEM replacement sensor, ensuring the mechanical linkage aligns correctly with the sensor's rotary input.

6. 6

   Reassemble

   Secure the mounting hardware and reconnect the electrical harness. Reconnect the battery.

7. 7

   Calibration

   A calibration cycle must be performed after replacing the potentiometer to prevent false errors. Depending on the model, this may require the Case IH Electronic Service Tool (EST) or an in-cab calibration sequence (e.g., entering the H-Menu or holding specific transmission buttons while starting the engine) to teach the ECU the new minimum and maximum voltage values of the pedal.