New Holland 2326 – TCM: Transmission Powershift Sensing System Speed Sensor Fault

The Transmission Control Module (TCM) has detected an illogical signal from the transmission speed sensors. This typically occurs when the Engine torque/RPM sensor wiring has been incorrectly swapped with either the transmission mid-speed or output-speed sensor harnesses, resulting in a cross-connection. A less common cause for this code is the controller measuring excessively high engine RPM sourced from the alternator.

• T7.220
• T7.235
• T7.250
• T7.260
• T7.270
• T8 Series
• TG Series
• Ford 8730
• TS115A
• T6 Series

1. 1

   Verify that each sensor is plugged into its correct corresponding harness, as a swapped connection is the primary cause of this fault

2. 2

   Visually inspect the wiring harnesses and connectors for the engine RPM/torque sensor, transmission mid-speed sensor, and transmission output speed sensor for damage or corrosion

1. 1

   Safety First

   Park the machine on a level surface, engage the parking brake, and disconnect the battery before working on electrical components.

2. 2

   Locate Sensors

   Identify the physical locations of the Engine torque/RPM sensor, the transmission mid-speed sensor, and the transmission output speed sensor using the machine's service manual.

3. 3

   Verify Connections

   Trace the wiring from each of these sensors back to its connector and ensure it is plugged into the correct harness. The fault code implies this is the most likely cause of the issue.

4. 4

   Correct Connections

   If any sensors are found to be swapped, disconnect them and reconnect them to their proper harnesses.

5. 5

   Inspect Connectors and Wiring

   If the sensors are correctly connected, unplug each one and inspect the connector pins for damage, corrosion, or a loose fit. Clean the connectors if necessary. Check the wiring for any visible damage, chafing, or breaks.

6. 6

   Test the Sensor (If Necessary)

   If the wiring and connections are correct and the fault persists, the sensor itself may be faulty. You can test a magnetic-type sensor with a multimeter set to Ohms. Resistance values can vary, but a reading that is extremely high, low, or shows an open loop ("OL") may indicate a faulty sensor.

7. 7

   Clear Fault Codes

   After performing repairs, reconnect the battery and use a diagnostic tool to clear the fault codes from the transmission controller.

8. 8

   Test Drive

   Operate the machine to verify that the fault code does not reappear and that the transmission is shifting correctly.