New Holland NH 3125 – Engine Control Unit (ECU / EDC): Hand Throttle potentiometer 2 Low error.

This code indicates that the signal voltage from the second track (Potentiometer 2) has fallen below the minimum acceptable threshold. This typically points to a short to ground, an open circuit in the signal wire, a loss of the 5-volt reference, or a complete internal failure of the potentiometer's resistance track.

• T6010
• T6030
• T6050
• T6070
• T8010
• T8030
• T9020
• T9050
• TM115
• TM190
• TS100A
• TS115A
• TL90
• TL100
• TG215
• TJ275
• TJ330

1. 1

   Inspect the hand throttle lever mechanism on the right-hand console or armrest for physical damage, excessive play, or debris that might be forcing the sensor past its mechanical stop.

2. 2

   Unplug the 3-pin connector at the hand throttle potentiometer to inspect for corrosion, bent pins, or backed-out terminals, and trace the wiring harness down the armrest to check for chafed wires causing a short to ground.

3. 3

   Turn the key ON (engine off) and use a multimeter to verify that the connector is receiving a steady 5-volt reference signal from the ECU and has a solid ground.

4. 4

   Back-probe the signal wire for Potentiometer 2 and perform a signal sweep test by slowly moving the hand throttle from idle to full throttle to ensure the voltage changes smoothly without dropping out.

5. 5

   Use the New Holland Electronic Service Tool (EST) to view live data for Hand Throttle Pot 1 and Pot 2 to verify they track together; if Pot 1 is normal but Pot 2 is flatlined low, the sensor is faulty.

1. 1

   Power Down

   Turn off the ignition and disconnect the negative battery cable to prevent electrical spikes.

2. 2

   Access the Sensor

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

3. 3

   Disconnect

   Unplug the electrical connector from the faulty hand throttle potentiometer.

4. 4

   Remove

   Remove the retaining fasteners (usually small Torx or Phillips screws) holding the potentiometer to the throttle lever assembly. Carefully slide the sensor off the throttle shaft.

5. 5

   Install

   Align the new potentiometer with the D-shaft or slotted shaft of the throttle lever. Secure it with the retaining screws. Note: Do not overtighten, as the plastic housing can crack easily.

6. 6

   Reconnect

   Plug the electrical connector back in and reassemble the console trim.

7. 7

   Calibrate

   Reconnect the battery. Turn the key to the ON position. Depending on the specific New Holland model, perform a throttle calibration routine (either via the tractor's instrument cluster H-Menu or using the New Holland EST laptop) so the ECU can learn the new minimum and maximum voltage values of the replacement sensor.