21220559 Level Sensor | Genuine Volvo Penta Part

🔧 Product Description

Genuine reducing-agent level sensor used in Volvo Penta SCR/AdBlue aftertreatment tanks. It monitors DEF/AdBlue level for the engine and aftertreatment controller and belongs to a documented Volvo commercial and industrial sensor family.

⚙️ Key Features

• SCR/AdBlue tank level measurement
• Used in industrial diesel aftertreatment systems
• Provides level data for dosing control and derate protection
• Large documented Volvo OEM number family

🔌 Function

The sensor measures the quantity of AdBlue/DEF in the reducing-agent tank and sends the value to the aftertreatment control system.

⚠️ Common Signs of Failure

• Incorrect or fluctuating AdBlue level reading
• SCR or dosing-system warning
• Engine derate caused by an implausible level signal
• Crystallisation around the sensor

🛠️ Service Notes

• Note the wiring and the sensor's orientation before removal, and isolate the circuit so nothing is live while the sender is out
• Check the float or probe moves freely through its full travel before fitting, and that nothing inside the tank or reservoir can foul it
• Seal the thread or flange as the installation specifies, and be sparing with sealant on a sender that earths through its body — an insulated sender reads nothing at all
• Do not over-tighten; these are thin-walled sensor bodies going into thin-walled tanks and housings
• Prove the installation end to end afterwards, confirming the gauge or alarm responds correctly at both ends of the range rather than assuming a new part must be good

🔄 Supersession & Cross Reference

OEM / Related Numbers

• 20802577 related reference
• 21076524 related reference
• 21596913 related reference
• 21876315 related reference
• 7420802577 related reference
• 7421076524 related reference

Aftermarket / Verified Equivalents

• DT Spare Parts: 6.33954
• DT Spare Parts: 6.33954SP

📦 Condition

• Genuine Volvo Penta part
• Brand new
• Supplied in original or equivalent packaging