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Detroit Diesel  |  SKU: DDE EA0001404878

DDE EA0001404878 | Genuine Detroit Diesel® DEF Metering Unit

Regular price $49500
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Part Number: DDE EA0001404878
Condition: New
Manufacture/Brand: Detroit Diesel
Related Part Numbers: DDEEA0001404878, A0001404039, A0001405539

Description:
A DEF metering unit — also known as a DEF doser, urea metering unit, or DEF dosing module — is a key component of the Selective Catalytic Reduction (SCR) emissions system on diesel-powered vehicles. It precisely controls the flow of Diesel Exhaust Fluid (DEF) into the exhaust stream. DEF Metering Unit, Doser Pump, Emission Metering Module 12V, UL2 type, 2014-2021

Fits For 
Detroit Diesel / Daimler (Freightliner / Western Star etc.) engine / chassis setups
Engines:
Detroit Diesel DD13, DD15, DD15

Purpose:

 The DEF metering unit’s main job is to:
  1. Draw DEF from the tank

  2. Measure and regulate how much DEF is injected

  3. Deliver DEF to the dosing valve (injector), which sprays it into the hot exhaust gases

The DEF then converts harmful NOₓ (nitrogen oxides) into harmless nitrogen and water vapor — helping the vehicle meet strict emissions regulations (EPA, CARB, Euro 6, etc.).


Signs of a Bad DEF Metering Unit

Check engine light or emissions-related fault codes (e.g. SPN 4334, 5246)

DEF dosing inactive or system “derate”

Excessive DEF consumption

Crystallized DEF buildup around dosing valve

Inaccurate NOₓ readings / failed emissions tests

 

About the Manufacturer – Detroit Diesel:

Detroit Diesel is a leading American manufacturer of heavy-duty diesel engines, transmissions, and aftertreatment systems, primarily for the commercial trucking industry. Founded in 1938 and now a subsidiary of Daimler Truck North America, Detroit is best known for its DD Series engines — including the DD13, DD15, and DD16 — which power Freightliner and Western Star trucks.

Detroit also produces advanced technologies such as Detroit™ Axles, Detroit™ Connect telematics, and integrated powertrains, offering fleet operators improved fuel efficiency, uptime, and diagnostics. The company is headquartered in Detroit, Michigan, and continues to play a central role in modernizing emissions systems and performance standards in heavy-duty transportation.