Fendt 1.2.52 – Engine Control Unit (ECU) / EDC 7 / EMR2/EMR3: B086 - Rail pressure sensor

Break in the wiring or a short circuit for the B086 Rail pressure sensor. The engine will automatically shut down after approximately 4 to 5 minutes to protect the fuel system.

• 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
• 309 Vario
• 310 Vario
• 311 Vario
• 312 Vario
• 409 Vario
• 410 Vario
• 411 Vario
• 412 Vario
• 711 Vario
• 712 Vario
• 714 Vario
• 716 Vario
• 815 Vario
• 817 Vario
• 818 Vario
• 916 Vario
• 920 Vario
• 924 Vario
• 926 Vario
• 930 Vario

1. 1

   Wait at least 1 minute after shutting off the engine for the high-pressure fuel system to depressurize before performing any checks.

2. 2

   Visually inspect the wiring harness leading to the B086 sensor for a cable break or short circuit (refer to Fendt electrical wiring diagram Sheet 36).

3. 3

   Unplug the sensor and check for corrosion, pushed-out pins, or moisture inside the connector.

4. 4

   Use the SERDIA diagnostic tool to read specific sub-fault codes (FC: 00D1, 00D2) and monitor live rail pressure data (normal operating pressure is 400 to 1600 bar).

1. 1

   Preparation

   Disconnect the negative battery terminal. Ensure the engine has been off for at least 1 minute to allow the common rail pressure to drop to zero. Clean the area around the sensor to prevent dirt from entering the fuel rail.

2. 2

   Removal

   Unplug the electrical harness connector from the B086 sensor. Use a socket wrench to carefully unscrew the old rail pressure sensor from the fuel rail. Collect any draining fuel with a rag and dispose of it properly.

3. 3

   Cleaning

   Wipe the sealing surface of the fuel rail mounting port.

4. 4

   Installation

   Thread the new rail pressure sensor in by hand to prevent cross-threading.

5. 5

   Torque

   Using a torque wrench and the appropriate socket insert, tighten the rail pressure sensor to 70 Nm.

6. 6

   Reassembly

   Reconnect the electrical harness connector until the latch clicks. Reconnect the battery.

7. 7

   Testing

   Turn the ignition key to the ON position without starting the engine. Use the SERDIA diagnostic tool to clear the stored fault codes (00D1, 00D2). Start the engine, verify that the fault does not return, and visually inspect the sensor fitting for fuel leaks.