Case IH 19568 (DTC F28F) - ECU – DCU (Dosing Control Unit) or Engine Control Unit (ECU) / Tractor Systems Module: DEF/AdBlue level too low warning is active - Stage 2

The system has detected that the Diesel Exhaust Fluid (DEF) / AdBlue level in the tank has dropped below the critical "Stage 2" threshold. This triggers an amber or red warning light on the dash and will typically induce an engine power reduction (limp mode/torque reduction) to comply with emissions regulations. This code can be triggered by a genuinely empty tank or a malfunctioning DEF tank level sensor.

• MAXXUM T4E
• Magnum 180
• Magnum 210
• Magnum 260
• Magnum 315
• Magnum 340
• Magnum 370
• Steiger 350
• Steiger 400
• Steiger 450
• Steiger 500
• Steiger 550
• Steiger 600
• Rowtrac
• Puma
• Maxxum
• Farmall
• Luxxum
• 240 Series Axial-Flow Combines
• 7230
• 8230
• 9230
• Patriot sprayers
• Titan floaters
• Farmlift telehandlers

1. 1

   Physical Fluid Check: Verify the actual DEF/AdBlue fluid level in the tank. Ensure the fluid is not contaminated.

2. 2

   Check for Related Sensor Codes: Scan the ECU/DCU for other active fault codes. If codes 19650 (DEF/AdBlue tank level sensor voltage too high) or 19651 (DEF/AdBlue tank level sensor voltage too low) are present, the issue is electrical/sensor-related, not a genuinely empty tank.

3. 3

   Wiring & Connector Inspection: Ensure the heated DEF level sensor is properly connected. Check the wiring harness between the sensor and the DCU for shorts, open circuits, or corrosion.

4. 4

   Supply Module & Line Inspection: Inspect the DEF supply module inlet connector, outlet connector, and hoses for blockages, leaks, or defects.

1. 1

   Refill the Tank

   If the tank is physically low, fill the DEF/AdBlue tank with clean, ISO 22241-compliant fluid to the proper level.

2. 2

   Clear Codes

   Use an Electronic Service Tool to clear the fault codes. Restart the machine and check if the code returns.

3. 3

   Address Sensor Faults

   If the tank is full but the code persists (or if sensor voltage codes are active), the DEF tank level sensor is likely defective and sending a false "empty" signal. Replace the DEF tank level sensor.

4. 4

   Service the Supply Module

   If the sensor is functioning properly, check the DEF supply module main filter. Replace the filter if it is clogged and restricting fluid flow.

5. 5

   Replace the Supply Module

   If the fluid level is correct, the sensor is verified good, the lines are clear, and the fault code still cannot be cleared or returns, the NOx neutralization unit / DEF supply module (pump) is defective and must be replaced.