Fendt 1.2.9B – EDC Control Module (A021) / Pump Control Unit (A020): Engine control module / pump control unit (EDC) — Engine stop via engine stop solenoid valve

This code indicates a plausibility error regarding the 'Engine Stop via Solenoid valve' (MAB-Signal). The system detects that the MAB-Status in the Pump Control Module (A020) and the EDC Control Module (A021) are not identical. The system will either initiate an engine stop or enter a restricted power mode (fuel flow reduced by 25-40% and maximum engine speed limited to 1900 RPM).

• 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
• Farmer 409
• Farmer 410
• Farmer 411
• Farmer 412
• Favorit 711
• Favorit 712
• Favorit 714
• Favorit 716
• Favorit 815
• Favorit 817
• Favorit 818
• Favorit 916
• Favorit 920
• Favorit 924
• Favorit 926
• Favorit 930

1. 1

   Check Relay K021 ('Relay solenoid valve engine stop') located at the right rear in the cab (behind the cover) to ensure it is functioning and not stuck open/closed.

2. 2

   Check the wiring harness for continuity, corrosion, or shorts between the Pump Control Module (A020) and the EDC Control Module (A021).

3. 3

   Verify the resistance and voltage at the engine stop solenoid valve to ensure it is receiving the correct signal and operating within spec.

4. 4

   Record the failure and ambient parameters using the FENDIAS diagnostic tool, clear the fault code memory, and run the machine to see if the code returns.

1. 1

   Disconnect Battery

   Always disconnect the battery before working on the EDC electrical system.

2. 2

   Access Relay Panel

   Remove the cover at the right rear of the cab to access the relay board.

3. 3

   Test/Replace Relay K021

   Swap Relay K021 with a known good relay of the same type. If the fault clears, replace the relay permanently.

4. 4

   Inspect Harness

   Trace the wiring from the EDC module to the injection pump control unit. Repair any chafed wires, clean the connector pins with contact cleaner, and ensure a tight connection.

5. 5

   Replace Solenoid Valve

   If the wiring and relay are intact but the solenoid has incorrect resistance values or fails to actuate mechanically, remove the defective engine stop solenoid valve from the injection pump and install a new one.

6. 6

   Clear Codes

   Reconnect the battery, connect the FENDIAS tool, clear the EDC fault memory, and test run the engine to confirm full power is restored and the code does not return.