Case IH 11021 – Engine Controller (ENG): Decelerator Position Sensor voltage is too low

The Engine Controller (ECM) has detected that the voltage signal from the decelerator pedal (or hand throttle) position potentiometer has dropped below the acceptable minimum threshold. This typically indicates an open circuit, a short to ground in the sensor wiring, or an internal failure of the potentiometer itself.

• STX Steiger
• MX Magnum series
• Steiger series
• Steiger 380
• Steiger 430
• Steiger 535

1. 1

   Calibration Check: Ensure the decelerator pedal position potentiometer is correctly calibrated. The pedal must be fully depressed and return properly during the calibration procedure.

2. 2

   Mechanical Inspection: Inspect the decelerator pedal stop bolt and linkage. A loose stop bolt or worn skid/shoe can cause the pedal to travel out of its physical range, dropping the voltage below the threshold.

3. 3

   Harness Inspection: Inspect the wire harness running from the Engine Controller to the decelerator position potentiometer. Look for chafed wires, disconnected pins, or corrosion.

4. 4

   Electrical Testing: Use a multimeter to test the circuit for an open wire or a short to ground. Verify that the sensor is receiving its 5-volt reference supply from the controller.

1. 1

   Turn off the machine, remove the key, and disconnect the battery to ensure electrical safety.

2. 2

   Locate the decelerator pedal assembly inside the cab.

3. 3

   Inspect the mechanical components (Decelerator Rod, Skid/Shoe, and Extension Spring) for binding or excessive wear.

4. 4

   Disconnect the electrical harness connector from the throttle/decelerator control potentiometer.

5. 5

   If harness damage was found during diagnostics, repair the open or shorted wire.

6. 6

   If the wiring is intact, remove the mounting hardware (typically M4 screws and lock nuts) securing the potentiometer to the throttle bracket.

7. 7

   Install the new potentiometer and secure it with the mounting hardware.

8. 8

   Reconnect the electrical harness to the sensor.

9. 9

   Reconnect the battery and perform a throttle/decelerator calibration procedure via the machine's display to ensure the controller recognizes the new sensor's voltage sweep.