Case IH 19568 (F-1761-18) – DCU (Dosing Control Unit) or Engine ECU: DEF/AdBlue level too low warning is active - Stage 2

This condition indicates that the NOx neutralization unit (power module) has detected that the Diesel Exhaust Fluid (DEF) / AdBlue level has dropped below the critical "Limit 2" threshold. This error is triggered either because the fluid tank is physically empty/too low, or because the DEF tank level sensor is faulty and sending an incorrect low-level signal.

• VESTRUM CVX
• Magnum (235–340 Series 4, 315, 340)
• Steiger (350–600)
• Puma
• Optum
• Farmall
• 240 Series Axial-Flow Combines (7230, 8230, 9230)

1. 1

   Physically inspect the DEF/AdBlue tank to verify the actual fluid level. Do not rely solely on the cab display.

2. 2

   Check that the heated DEF level sensor is properly connected. Inspect the pins and terminals at the sensor connector for oxidation, corrosion, or "pin back out" (pushed-out pins).

3. 3

   Check for continuity between the ACM/DCU and the Urea level sensor connector.

4. 4

   Check the voltage at the Urea level sensor connector. Typical Bosch system voltage parameters across the signal pins are: < 4.75 V = 100% Tank full, 2.0 – 3.0 V = 50% Tank full, > 0.3 V = Tank Empty.

5. 5

   Check if there are other active fault codes (such as 19650 or 19651 for sensor voltage too high/low). Resolve those electrical faults first, as they can trigger the 19568 code.

6. 6

   Ensure all connectors on the NOx neutralization unit / supply module are securely connected and that the DEF lines are not pinched or leaking.

1. 1

   Refill the Tank

   If the fluid level is genuinely low, refill the DEF/AdBlue tank to the proper level. Cycle the key and check if the fault code clears.

2. 2

   Repair Wiring

   If the tank is full but the code persists, and your diagnostic checks revealed damaged wiring or corroded connector pins, repair the harness or replace the connector pigtail.

3. 3

   Replace the Level Sensor / Header

   If the wiring is intact but the sensor voltage readings are out of specification (indicating a failed internal float or sensor board), replace the DEF tank level sensor. On most Case IH machines, this is integrated into the "DEF Header" or suction unit.

4. 4

   Replace the Supply Module

   If the fault code does not clear or immediately recurs after replacing the sensor and verifying the wiring, the NOx neutralization unit (DEF Supply Module / Doser Pump) may have an internal failure and must be replaced. Note: Replacing the module may require a dealer laptop to program the engine software to the new component.