Deutz-Fahr T50 – Hydraulic Shuttle Control Unit: Shuttle output speed sensor is disconnected (open circuit)

The system is failing to receive a valid speed signal from the hydraulic shuttle, which is critical for the tractor to manage forward/reverse directional changes and transmission engagement.

• Agroplus 310, 320, 410, and 420 Profiline series tractors
• Deutz-Fahr Agrofarm series (410, 420, 430, 85, 100)
• Deutz-Fahr Series 5D (including VSF CVT / TTV models)
• SAME Explorer 90
• SAME R3 EVO 85, 100, 110

1. 1

   Cycle the power by turning the starter key to the OFF position, and then back to the ON position to rule out a temporary software glitch

2. 2

   Inspect the wiring harness from the Hydraulic Shuttle ECU to the shuttle output speed sensor for severed wires, chafing, or a physically disconnected plug

3. 3

   Use a multimeter to verify that the sensor is receiving the correct reference voltage from the ECU

4. 4

   Check the sensor for internal continuity (if the sensor reads as an open circuit internally, it has failed)

1. 1

   Prep the Machine

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

2. 2

   Locate the Sensor

   Locate the shuttle output speed sensor on the transmission/hydraulic shuttle housing.

3. 3

   Inspect and Clean

   Disconnect the sensor's electrical connector. Clean out any oil, dirt, or moisture, and ensure the pins are not pushed back or corroded.

4. 4

   Harness Repair (If Applicable)

   If the diagnostic checks revealed a break in the wiring harness, repair the wiring using appropriate weatherproof connectors and re-loom the harness.

5. 5

   Replace the Sensor (If Applicable)

   If the wiring and power supply are intact but the sensor failed the continuity test, remove the sensor's retaining bolt and pull the sensor from the housing. Lubricate the O-ring on the new sensor with clean transmission oil, insert it into the housing, and torque the retaining bolt to factory spec.

6. 6

   Re-test

   Reconnect the wiring harness, turn the ignition on, and verify that the T50 code has cleared from the instrument panel display.