Fendt 0F.1.05 – Central Electrical System ECU (A038): Non-operable function in main beam (high beam) drive headlights

The tractor's system detects that the main beam circuit is open or faulty. As a safety consequence, the tractor's electrical system will automatically switch over to the additional/auxiliary headlights to maintain visibility.

• 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 400 Vario COM III
• Fendt 700 Vario COM III
• Fendt 700 Vario SCR
• Fendt 800 Vario COM III
• Fendt 800 Vario SCR
• Fendt 820 Vario greentec COM III
• Fendt 900 Vario COM III (e.g., 916, 920, 924, 926, 930)
• Fendt 900 Vario SCR

1. 1

   Check if the main beam headlights are completely out and verify that the tractor has successfully auto-switched to the additional headlights.

2. 2

   Inspect the left and right headlight bulbs to see if the main beam filaments are blown.

3. 3

   Inspect the wiring harness and connectors at the headlight housings for corrosion, moisture ingress, or loose pins.

4. 4

   Consult Circuit Diagram Sheet 13 to trace the wiring from the Central Electrical System ECU (A038) to the E098 and E100 headlight components.

5. 5

   Use a multimeter to test the voltage output at the headlight connectors when the main beam is activated to determine if the ECU is sending power.

1. 1

   De-energize

   Turn off the tractor ignition and remove the key to ensure the electrical system is de-energized.

2. 2

   Access the Housings

   Open the bonnet/hood to access the rear of the front headlight assemblies.

3. 3

   Disconnect

   Unplug the electrical harness connectors from the back of the left and right headlights.

4. 4

   Remove Bulbs

   Remove the rubber dust boots and retaining clips, then extract the headlight bulbs.

5. 5

   Replace Bulbs

   If the bulbs are blown, replace them with new H4 or R2 halogen bulbs (or LED equivalents). Note: Do not touch the glass of new halogen bulbs with your bare hands, as oil from your skin can cause premature failure.

6. 6

   Repair Wiring (If Necessary)

   If the bulbs are intact, use a multimeter to check for continuity in the wiring harness back to the Central Electrical System ECU. Repair any broken wires or clean corroded ground connections.

7. 7

   Reassemble

   Reinstall the bulbs, secure the retaining clips, replace the dust boots, and reconnect the wiring harnesses.

8. 8

   Test

   Turn on the tractor ignition and test the main beam headlights.

9. 9

   Clear Codes

   Clear the fault code from the tractor's terminal using the fault code confirmation/deletion sequence on the multiple display (pressing the terminal button until the fault symbol flashes, then confirming the deletion).