DZ121770 | Genuine John Deere® Doser Fluid Supply Module 2.2 12V, 3 Outlet

Reduce NOx Emissions

• Injects the right amount of DEF into the exhaust, which reacts in the SCR (Selective Catalytic Reduction) catalyst to convert harmful NOx into harmless nitrogen (N₂) and water (H₂O).

Meet Emission Regulations

• Ensures compliance with strict standards such as Euro 6, EPA Tier 4 Final, and other regional diesel emission laws.

Protect the Environment and Health

• Reduces smog-forming NOx pollutants, protecting air quality and reducing respiratory hazards.

Support Engine Efficiency

• By controlling NOx chemically instead of mechanically limiting combustion, the engine can operate efficiently without sacrificing power.

Enable Precise DEF Usage

• The module ensures exact dosing, preventing overuse of DEF (wasteful) or underuse (ineffective emission reduction).

DEF/AdBlue Warning Light

• Dashboard lights may indicate low DEF flow, system malfunction, or dosing errors.

Check Engine Light or SCR Fault Codes

• The ECU may detect improper dosing and trigger engine fault codes.

Reduced Engine Power (Limp Mode)

• Many modern diesel engines limit power to protect the engine when the SCR system is not functioning correctly.

Increased NOx Emissions / Failed Emissions Test

• A malfunctioning doser module can prevent proper NOx reduction, causing failed emissions inspections.

Frequent or Failed SCR Regeneration

• If DEF is not being injected correctly, the SCR catalyst cannot reduce NOx efficiently, leading to repeated regeneration attempts or failure.

Unusual DEF Usage

• Overuse (leak or over-injection) or underuse (blockage or pump failure) of DEF can indicate a problem with the module.

Strange Noises from Module

• A failing pump inside the doser module may produce unusual buzzing or grinding sounds.