Case IH 3001 – Engine Control Unit (ECU): Diagnostic fault check of synchronism for double potentiometer and Low Idle Switch (LIS)

The controller is performing a plausibility check between the two potentiometer tracks (APP1 and APP2) inside the accelerator pedal and the Low Idle Switch (LIS). The fault triggers when the voltage signals from the pedal's position sensor do not match the physical on/off state of the idle switch (e.g., the sensor indicates the pedal is pressed, but the idle switch indicates it is at rest, or vice versa).

• Steiger T4B
• Case IH Steiger tractors
• Case IH Magnum tractors (MX210, MX230, MX255, MX285, 215, 245, 275, 305)
• Case IH Puma tractors (165, 180, 195, 210, 225)
• Case IH Maxxum tractors
• Case IH CX and MX Series tractors
• Case IH 240 Series Axial-Flow Combines

1. 1

   Wiring and Harness Inspection: Check the wiring harness between the accelerator pedal and the ECU for broken, disconnected, or shorted wires.

2. 2

   Connector Check: Inspect the connectors at both the foot pedal and the ECU for corrosion, backed-out pins, or moisture.

3. 3

   Plausibility Test: Using a diagnostic tool, monitor the live data for APP1 and APP2 (the double potentiometers) to ensure they scale smoothly without voltage dropouts as the pedal is depressed.

4. 4

   Low Idle Switch Test: Verify that the Low Idle Switch state changes correctly in the diagnostic live data when the pedal is moved off its resting position.

1. 1

   Turn off the machine and disconnect the battery

   This prevents electrical shorts or ECU damage.

2. 2

   Locate the foot throttle pedal assembly

   Locate the assembly in the cab.

3. 3

   Disconnect the electrical harness connector

   Disconnect it from the pedal assembly.

4. 4

   Inspect the wiring and connector

   If wiring damage or high resistance is found, repair the harness.

5. 5

   Unbolt the defective accelerator pedal assembly

   If the wiring is intact, the fault is due to an aged or defective internal sensor/switch. Unbolt the defective accelerator pedal assembly from the cab floor.

6. 6

   Install the replacement OEM accelerator pedal assembly

   Secure the mounting hardware.

7. 7

   Reconnect the electrical harness

   Reconnect it to the new pedal.

8. 8

   Reconnect the battery

9. 9

   Clear the stored fault code and test operation

   Turn the key on and use a diagnostic tool to clear the stored 3001 fault code. Test the pedal operation to ensure the code does not return and the engine responds correctly.