Case IH tD1 – PCU (Power Control Unit) or Armrest Controller: Hand Throttle Position Sensor Potentiometer 1 Over Voltage

The control module is receiving a voltage signal from the primary potentiometer circuit of the hand throttle that is higher than the maximum expected threshold (typically near or above 5.0V). This condition is usually caused by a short to power in the signal wire, an open ground circuit on the sensor, or an internal failure of the potentiometer itself.

• MXM
• MXM Series
• MXM 120
• MXM 130
• MXM 140
• MXM 155
• MXM 175
• MXM 190

1. 1

   Inspect the wiring harness leading to the hand throttle assembly on the right-hand console/armrest for chafed wires, pinched harnesses, or broken connections (especially an inch or two below the plug).

2. 2

   Disconnect the sensor and turn the key to the 'ON' position. Use a multimeter to verify that the sensor is receiving a steady 5V reference signal and has a solid ground.

3. 3

   Test the signal wire for continuity to a 12V power source. If voltage is present on the signal wire when disconnected from the sensor, the harness is shorted.

4. 4

   Measure the resistance across the sensor's pins while slowly moving the hand throttle lever. The resistance should change smoothly. If it reads infinite resistance (open) or has dead spots, the sensor is internally faulty.

1. 1

   Power Down

   Turn off the tractor and disconnect the negative battery cable to protect the PCU/Armrest controller.

2. 2

   Access the Sensor

   Remove the trim panels on the right-hand console or armrest to expose the hand throttle lever assembly.

3. 3

   Remove the Faulty Component

   Disconnect the electrical connector from the hand throttle potentiometer. Remove the retaining screws/clips holding the potentiometer to the throttle lever mechanism and extract the sensor.

4. 4

   Install the New Part

   Mount the replacement potentiometer, secure the fasteners, and plug in the electrical connector.

5. 5

   Reassemble and Power Up

   Reinstall the console trim panels and reconnect the battery.

6. 6

   Calibration

   Enter the tractor's 'H-Menu' (Calibration mode) and perform the Transmission/EDC and throttle calibration procedures so the PCU can learn the new minimum and maximum voltage sweeps of the replacement sensor.