Fendt 04.1.58 – A050 - ECU, basic control unit: Transmission slip monitor

Transmission output speed deviates by more than 30% from the setpoint value. The system monitors this using the B014 and B015 Hall sensors. If the actual output speed does not match the expected ratio, this slip fault is triggered and the Tractor Management System (TMS) is automatically switched off.

• 922 Vario COM III
• 924 Vario COM III
• 927 Vario COM III
• 930 Vario COM III
• 933 Vario COM III
• 936 Vario COM III
• Fendt 300 Vario (COM III)
• Fendt 400 Vario (COM III)
• Fendt 700 Vario (COM III, SCR)
• Fendt 800 Vario (COM III, S4)
• Fendt 900 Vario (COM III, SCR) (e.g., 916, 920, 922, 924, 926, 927, 930, 933, 936)

1. 1

   Determine if the tractor is operating in extremely low temperatures.

2. 2

   Check the clutch pedal sensor (B017) and the actuator unit (A009) to ensure the clutch is engaging/disengaging properly.

3. 3

   Test the signals from the B014 (hydrostatic collecting shaft) and B015 (bevel pinion) Hall sensors. Look for damaged wiring, poor connections, or a loss of the 8.5V supply voltage.

4. 4

   Check the transmission oil temperature and condition.

1. 1

   Warm-Up / Fluid Check

   If the tractor is cold, allow it to reach normal operating temperature. Check the transmission oil level and inspect for burnt fluid.

2. 2

   Inspect Wiring

   Trace the wiring harnesses from the A050 Basic Control Unit to the A009 Actuator Unit, B014 sensor, and B015 sensor. Repair any chafed wires or corroded connector pins.

3. 3

   Test/Replace Sensors

   Using a multimeter or oscilloscope, verify the speed signals from the B014 and B015 sensors while the tractor is moving. If either sensor drops the signal or provides erratic readings, replace the faulty sensor(s).

4. 4

   Inspect Actuator Unit (A009)

   If the sensors are reading correctly but the transmission is physically slipping, inspect the A009 actuator unit and the clutch mechanism for mechanical failure or sticking valves. Replace the actuator unit if it fails to hold the commanded ratio.

5. 5

   Calibration

   After replacing any transmission sensors, the actuator unit, or the A050 ECU, you must perform a transmission calibration (Teach-in / EOL programming) using the tractor's diagnostic terminal to relearn the neutral positions and travel ranges.