New Holland NH 3122 – Engine Control Module (ECM) / Electronic Diesel Control (EDC): PTO Torque sensor short circuit

The control module is receiving an implausibly low or zero voltage signal from the PTO twist/torque sensor, indicating that the sensor's signal wire is shorted directly to a ground source, or the sensor itself has failed internally.

• T8.275
• T8.300
• T8.355
• T8.380
• T8.420
• T7.175
• T7.190
• T7.220
• T7.235
• T7.250
• T7.260
• T7.270
• TG210
• TG230
• TG255
• TG285
• T6000 Series

1. 1

   Locate the PTO twist/torque sensor on the rear PTO housing and visually inspect the wiring harness for damage, rubbing, or pinched wires that could cause a short to the chassis (ground).

2. 2

   Disconnect the 3-pin connector at the PTO twist sensor and check for moisture, dirt, or bent/corroded pins.

3. 3

   With the sensor disconnected and the key ON, use a multimeter to test the harness side for the 12V sensor supply voltage from the ECM.

4. 4

   Test the signal wire for continuity to ground. If the signal wire is grounded while disconnected from the sensor, the wiring harness is shorted and must be repaired. If the harness tests fine, the sensor itself has an internal short.

1. 1

   Power Down

   Turn off the tractor, remove the key, and engage the parking brake.

2. 2

   Remove the Sensor

   Disconnect the 3-pin electrical connector from the faulty PTO twist sensor on the PTO housing. Unbolt and remove the sensor.

3. 3

   Install the New Sensor

   Install the replacement PTO torque sensor and tighten it to OEM specifications. Reconnect the 3-pin electrical connector.

4. 4

   Calibrate the Sensor

   Access the tractor's H8 calibration menu via the cab display. Navigate to the PTO twist calibration screen (the display will show 'Pt'). Press and hold the downshift button to calibrate the PTO twist sensor. Once calibrated, the display will alternate between 'Pt' and the new calibration value.

5. 5

   Clear Codes

   Clear the stored NH 3122 fault code from the ECM and test the PTO under load to ensure the repair is successful.