Case IH PD1 – PCU (Powertrain Control Unit) / Tractor/Transmission Controller: Hand Throttle Position Sensor Potentiometer 1 Over Voltage

The control module is receiving a voltage signal from the primary hand throttle potentiometer that is higher than the maximum allowable threshold. This typically means the sensor has failed internally, the signal wire is shorted to a power source, or the sensor has lost its ground connection.

• MXM
• MXM Series
• MXM 120
• MXM 130
• MXM 140
• MXM 155
• MXM 175
• MXM 190
• Maxxum Series
• Puma Series
• TM Series
• T6000 Series
• T7000 Series

1. 1

   Inspect the wiring harness leading to the hand throttle position sensor in the cab console for chafed wires shorting to a power source.

2. 2

   Verify the ground pin at the sensor connector has continuity to the chassis/module ground (an open ground circuit frequently causes over voltage).

3. 3

   Perform a voltage sweep test by back-probing the sensor signal wire with a multimeter. Slowly move the hand throttle from idle to full throttle (voltage should scale smoothly between 0.5V and 4.5V).

4. 4

   Turn the key switch to the 'ON' position, disconnect the potentiometer, and then re-connect it to see if the PCU resets the active fault.

1. 1

   Power Down

   Turn off the tractor and disconnect the battery ground to prevent electrical spikes.

2. 2

   Access the Sensor

   Remove the side console/trim panels in the cab to access the base of the hand throttle lever assembly.

3. 3

   Remove the Faulty Sensor

   Unplug the electrical connector from the hand throttle potentiometer. Remove the retaining screws/clips holding the sensor to the throttle pivot mechanism.

4. 4

   Install the New Sensor

   Mount the replacement potentiometer, ensuring the mechanical tangs align correctly with the throttle lever slot. Secure the fasteners and plug in the connector.

5. 5

   Reassemble and Power Up

   Reinstall the console panels and reconnect the battery.

6. 6

   Calibration

   Enter the tractor's H-Menu (Calibration Setup Procedures) and perform the throttle/transmission calibration so the PCU learns the new sensor's minimum and maximum voltage values.