Fendt 4.1.58 – A050 - ECU, basic control unit: Transmission slip monitor — Transmission output speed deviates by more than 30% from setpoint.

The transmission's actual gear ratio deviates from the ideal/target gear ratio by more than 30%. The system detects that the slip values of the transmission ratios are beyond acceptable limits. In extremely cold ambient temperatures, this can occur as an isolated incident without causing damage. However, repeated occurrences under normal operating conditions indicate a severe issue that will cause oil overheating and serious transmission damage. When this fault is active, the Tractor Management System (TMS) is automatically switched off.

• 409 Vario
• 410 Vario
• 411 Vario
• 412 Vario
• 711 Vario
• 712 Vario
• 714 Vario
• 715 Vario
• 716 Vario
• 717 Vario
• 718 Vario
• 916 Vario
• 920 Vario
• 924 Vario
• 926 Vario
• 930 Vario
• 411 Vario COM III
• 412 Vario COM III
• 413 Vario COM III
• 414 Vario COM III
• 415 Vario COM III
• 712 Vario COM III
• 714 Vario COM III
• 716 Vario COM III
• 718 Vario COM III
• 818 Vario COM III
• 820 Vario COM III
• Farmer 400 Vario
• 409
• 410
• 411
• 412
• Favorit 700 Vario
• 711
• 712
• 714
• 716
• Favorit 900 Vario
• 916
• 920
• 924
• 926
• 930
• 933
• 936
• 939
• 300 Vario (COM II & COM III)
• 400 Vario (COM II & COM III)
• 700 Vario (COM II & COM III)
• 800 Vario (COM II & COM III)
• 900 Vario (COM II & COM III)

1. 1

   Determine if the tractor is operating in extreme cold, as thick oil can cause a single occurrence; warm the tractor up to see if the code clears

2. 2

   Verify if the fault is inactive when the turbo-clutch function is on (clutch pedal depressed)

3. 3

   Access the tractor diagnostics menu on the A008 terminal and compare the transmission adjustment values (IDEAL, VE, and REAL); heavy deviation of REAL indicates mechanical slip or sensor failure

4. 4

   Check the 8.5V power supply to the transmission sensors, often routed through A013 fuse 1 or 16

1. 1

   Stop Operation

   If the fault occurs under normal temperatures, stop driving immediately to prevent catastrophic transmission damage and oil overheating.

2. 2

   Inspect the Actuator Unit (A009)

   Check the mechanical connection between the A009 actuator unit and the actuator shaft. A faulty clutch on the actuator can cause this slip condition. Ensure the neutral points and maximum transmission ratio points are within specification.

3. 3

   Test the Speed Sensors

   Test the B014 (hydrostatic collecting shaft speed/direction sensor) and B015 (bevel pinion speed sensor) for plausibility. If the sensors are outputting mismatched speeds (plausibility error), the ECU will interpret this as transmission slip.

4. 4

   Inspect Wiring Harness

   Check the wiring harness for the transmission control circuit for breaks, corrosion, or short circuits between the A050 ECU, the A009 actuator, and the B014/B015 sensors.

5. 5

   Replace Defective Components

   If the A009 actuator clutch is slipping or the B014/B015 sensors are failing under load, replace them with genuine OEM parts.

6. 6

   Calibrate and Test

   After replacing any transmission control components, perform a transmission calibration. Take a test drive to ensure the actual gear ratio matches the ideal gear ratio and the fault does not return.