New Holland TRANS 38 – Transmission Controller (TCU): Shuttled to reverse when no wheel speed signal was available

The operator commanded a directional change (shuttling into reverse), but the transmission control system could not verify the machine's ground speed because the signal from the wheel speed sensor (or transmission output speed sensor) was missing, invalid, or out of range.

• TG210
• TG230
• TG255
• TG285
• TJ380
• T9050
• T7 Series
• T6000 Series
• Magnum Series
• MX/TG Series

1. 1

   Visually inspect the wheel speed sensor (mounted on the transmission housing) for physical damage, heavy debris buildup, or improper seating.

2. 2

   Inspect the wiring harness between the wheel speed sensor and the Transmission Controller for chafed wires, open circuits, or shorts to ground.

3. 3

   Disconnect the sensor and check the connector pins for corrosion, moisture, or bent terminals.

4. 4

   Use a multimeter to verify the sensor's resistance and voltage supply, comparing it to the specific OEM service manual specifications.

5. 5

   Ensure the transmission controller is receiving power and communicating properly with the CAN-bus system.

1. 1

   Park and secure tractor

   Park the tractor on a level surface, engage the parking brake, and turn off the engine.

2. 2

   Clean sensor area

   Clean the area around the wheel speed/transmission speed sensor on the transmission housing to prevent dirt from entering the transmission.

3. 3

   Disconnect harness

   Disconnect the electrical harness connector from the sensor.

4. 4

   Remove retaining bolt

   Remove the retaining bolt(s) securing the sensor to the housing.

5. 5

   Remove sensor

   Carefully pull the sensor out of the transmission housing. Have a catch pan ready, as a small amount of transmission fluid may leak.

6. 6

   Lubricate O-ring

   Lubricate the O-ring on the new OEM speed sensor with clean transmission fluid.

7. 7

   Install new sensor

   Insert the new sensor into the housing and tighten the retaining bolt to the specified OEM torque.

8. 8

   Reconnect harness

   Reconnect the electrical harness connector, ensuring it clicks into place.

9. 9

   Clear fault code

   Connect a diagnostic tool (such as the Jaltest diagnostic tool or CNH Electronic Service Tool) to clear the TRANS 38 fault code.

10. 10

    Test drive

    Test drive the tractor, shuttling between forward and reverse to verify the transmission shifts correctly and the code does not return.