Fendt 1.2.18 – Engine Control Unit (ECU) / EDC (Electronic Diesel Control) module: Pump control unit (injection pump) (EDC) needle movement sensor — Injection start system deviation

The start of injection is incorrectly set because the injection timing mechanism values are not within the specified tolerance. The system detects a deviation between the commanded injection timing and the actual injection timing measured by the needle movement sensor, resulting in restricted engine power and reduced end speed.

• 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
• 815 Vario
• 817 Vario
• 818 Vario

1. 1

   Check the overall fuel supply to ensure the injection pump is not being starved of fuel

2. 2

   Check the primary fuel pressure and the interior pressure of the injection pump (low interior pump pressure can prevent the timing advance mechanism from operating correctly)

3. 3

   Check the EDC level converter and the wiring to the needle movement sensor (NBF)

4. 4

   Run SERDIA diagnostic software to monitor live timing values and confirm the deviation

1. 1

   Inspect Fuel Supply

   Replace fuel filters and inspect supply lines for blockages, kinks, or air leaks that could cause pressure drops.

2. 2

   Test Pump Pressures

   Hook up a pressure gauge to test the primary supply pressure and the internal transfer pressure of the VP44 injection pump. If internal pressure is out of spec, the pump requires rebuilding or replacement.

3. 3

   Inspect the Sensor Harness

   Trace the wiring harness from the needle movement sensor (which is integrated into one of the fuel injectors) back to the EDC control unit. Look for chafing, corrosion, or loose pins.

4. 4

   Replace Faulty Components

   If fuel pressures are correct and the wiring is intact, the fault is caused by either a mechanically failing needle movement sensor (requiring replacement of that specific injector) or a failing timing piston/solenoid inside the VP44 injection pump.

5. 5

   Clear Codes

   After replacing the injector or injection pump, bleed the fuel system, start the tractor, and use SERDIA to clear the fault codes and verify that injection timing is now within tolerance.