Fendt 04.1.E2 – A050 - ECU, basic control unit: Pressure regulator control parameters in tractive power control not plausible (B008 / B039) or read incorrectly.

The system has detected a plausibility error between the B008 sensor (transmission drive pressure / high-pressure sensor 1) and the B039 sensor (push detection / high-pressure sensor 2). The control unit is receiving conflicting, missing, or incorrect readings from these sensors regarding the transmission's high-pressure circuit. The tractor will default to Emergency Mode, the TMS is switched off, and there is a loss of enhanced control functions.

• 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 309 Vario COM III
• Fendt 310 Vario COM III
• Fendt 311 Vario COM III
• Fendt 312 Vario COM III
• Fendt 409 Vario COM III
• Fendt 410 Vario COM III
• Fendt 411 Vario COM III
• Fendt 412 Vario COM III
• Fendt 413 Vario COM III
• Fendt 414 Vario COM III
• Fendt 415 Vario COM III
• Fendt 711 Vario COM III
• Fendt 712 Vario COM III
• Fendt 714 Vario COM III
• Fendt 716 Vario COM III
• Fendt 718 Vario COM III
• Fendt 815 Vario COM III
• Fendt 817 Vario COM III
• Fendt 818 Vario COM III
• Fendt 820 Vario COM III
• Fendt 916 Vario COM III
• Fendt 920 Vario COM III
• Fendt 922 Vario COM III
• Fendt 924 Vario COM III
• Fendt 926 Vario COM III
• Fendt 927 Vario COM III
• Fendt 930 Vario COM III
• Fendt 933 Vario COM III
• Fendt 936 Vario COM III

1. 1

   Check Sensor B008 (High-pressure sensor 1) wiring and supply voltage (should be 8.5V via A013 fuse 3 or 12V via A013 fuse 32, depending on model).

2. 2

   Check Sensor B039 (High-pressure sensor 2) wiring and supply voltage (typically 12V via A013 fuse 31).

3. 3

   Perform a signal voltage test on B008 during a high-pressure test (approx. 0.8 VDC at 0 bar/neutral, and 0.94 VDC at 30 bar/active stationary with engine speed >1400 rpm).

4. 4

   Inspect the wiring harness separation points (X157 for B008 and X177 for B039) for corrosion, moisture, or damaged pins.

1. 1

   Resolve Sensor/Wiring Faults

   If the diagnostic checks reveal a faulty B008 or B039 sensor, or a break in the wiring harness, replace the defective sensor or repair the wiring.

2. 2

   EOL Programming

   Once the physical repair is made, recalibrate the transmission parameters and clear the fault codes from the A050 ECU using FENDIAS diagnostic software.

3. 3

   ECU Repair/Replacement

   If the sensors and wiring are perfectly intact, the A050 Basic Control Unit itself may have suffered an internal hardware failure. Replace the A050 unit with a new OEM unit or send it to a specialized agricultural electronics repair service for bench-testing and board-level repair.