{"product_id":"a0001405539-genuine-detroit-diesel®-diesel-exhaust-fluid-dosing-unit","title":"A0001405539 | Genuine Detroit Diesel® Diesel Exhaust Fluid Dosing Unit","description":"\u003cp\u003e\u003cstrong\u003eDescription:\u003cbr\u003e\u003c\/strong\u003eA Diesel Exhaust Fluid (DEF) Dosing Unit \u003cstrong\u003eA0001405539 \u003c\/strong\u003eis a component in modern diesel vehicles that injects Diesel Exhaust Fluid into the exhaust system to reduce harmful emissions.\u003cbr\u003e\u003cbr\u003e\u003cstrong\u003ePart Number\u003c\/strong\u003e: A0001405539 \u003cbr\u003e\u003cstrong\u003eCondition\u003c\/strong\u003e\u003cspan\u003e: New\u003c\/span\u003e\u003cbr\u003e\u003cstrong\u003eManufacture\/Brand\u003c\/strong\u003e\u003cspan\u003e: Detroit Diesel\u003cbr\u003e\u003cstrong\u003eRelated Part Numbers\u003c\/strong\u003e: 0001405539, DDE-A0001405539, DDEA0001405539, RA0001405539, EA0001405539\u003cbr\u003e\u003c\/span\u003e\u003cstrong data-start=\"160\" data-end=\"176\"\u003e\u003cbr\u003e\u003c\/strong\u003e\u003cstrong\u003eFits A0001405539 \u003c\/strong\u003eFor\u003c\/p\u003e\n\u003ctable width=\"100%\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e \u003cstrong style=\"font-size: 0.875rem;\" data-start=\"417\" data-end=\"450\"\u003eDetroit Diesel \/ Freightliner\u003c\/strong\u003e\u003cspan style=\"font-size: 0.875rem;\"\u003e heavy trucks with SCR emissions systems\u003c\/span\u003e\n\u003cp\u003e– Especially on GHG17 \/ EPA10 emission spec engines\u003cbr data-start=\"546\" data-end=\"549\"\u003e– Used on models like Freightliner Cascadia with Detroit engines\u003cbr data-start=\"615\" data-end=\"618\"\u003e(DEF metering unit in the aftertreatment) \u003cspan class=\"\" data-state=\"closed\"\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp data-start=\"705\" data-end=\"919\"\u003e\u003cstrong data-start=\"705\" data-end=\"735\"\u003eMercedes-Benz heavy trucks\u003c\/strong\u003e such as the \u003cstrong data-start=\"748\" data-end=\"790\"\u003eActros MP4 \/ similar commercial trucks\u003c\/strong\u003e\u003cbr data-start=\"790\" data-end=\"793\"\u003e\u003cspan class=\"\" data-state=\"closed\"\u003e\u003c\/span\u003e\u003cbr\u003eTrucks and engines that require a DEF dosing system under \u003cstrong data-start=\"981\" data-end=\"1010\"\u003eEPA emissions regulations\u003c\/strong\u003e\u003c\/p\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003cp data-start=\"705\" data-end=\"919\"\u003e\u003cbr\u003e\u003c\/p\u003e\n\u003carticle class=\"text-token-text-primary w-full focus:outline-none [--shadow-height:45px] has-data-writing-block:pointer-events-none has-data-writing-block:-mt-(--shadow-height) has-data-writing-block:pt-(--shadow-height) [\u0026amp;:has([data-writing-block])\u0026gt;*]:pointer-events-auto scroll-mt-(--header-height)\" dir=\"auto\" data-turn-id=\"3f3b6bf9-203a-4bd7-8cf5-3c6d035daa00\" data-testid=\"conversation-turn-1\" data-scroll-anchor=\"false\" data-turn=\"user\" tabindex=\"-1\"\u003e\u003c\/article\u003e\n\u003cul id=\"catalogModels\" class=\"nav catalog\"\u003e\u003c\/ul\u003e\n\u003cp data-start=\"160\" data-end=\"353\"\u003e\u003cstrong\u003ePurpose of using A0001405539:\u003c\/strong\u003e\u003cstrong data-start=\"585\" data-end=\"597\"\u003e\u003cbr\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003ctable width=\"100%\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e\n\u003cstrong\u003e 1.  Inject DEF into the Exhaust\u003c\/strong\u003e\n\u003cp data-end=\"537\" data-start=\"521\"\u003e\u003cbr\u003eThe dosing unit:\u003c\/p\u003e\n\u003cul data-end=\"654\" data-start=\"538\"\u003e\n\u003cli data-end=\"593\" data-start=\"538\"\u003e\n\u003cp data-end=\"593\" data-start=\"540\"\u003eReceives signals from the engine control module (ECM)\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-end=\"654\" data-start=\"594\"\u003e\n\u003cp data-end=\"654\" data-start=\"596\"\u003eSprays a precise amount of DEF into the hot exhaust stream\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-end=\"732\" data-start=\"656\"\u003eAccuracy is critical — too much or too little affects emissions performance.\u003c\/p\u003e\n\u003cp data-end=\"766\" data-start=\"739\"\u003e\u003cstrong\u003e2. Reduce NOx Emissions\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp data-end=\"788\" data-start=\"767\"\u003eWhen DEF is injected:\u003c\/p\u003e\n\u003cul data-end=\"950\" data-start=\"789\"\u003e\n\u003cli data-end=\"827\" data-start=\"789\"\u003e\n\u003cp data-end=\"827\" data-start=\"791\"\u003eIt turns into ammonia in the exhaust\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-end=\"884\" data-start=\"828\"\u003e\n\u003cp data-end=\"884\" data-start=\"830\"\u003eInside the SCR catalyst, ammonia reacts with NOx gases\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-end=\"950\" data-start=\"885\"\u003e\n\u003cp data-end=\"950\" data-start=\"887\"\u003eHarmful NOx is converted into harmless nitrogen and water vapor\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-end=\"1016\" data-start=\"952\"\u003eThis allows the engine to meet strict environmental regulations.\u003c\/p\u003e\n\u003cp data-end=\"1052\" data-start=\"1023\"\u003e\u003cstrong\u003e3. Protect the SCR System\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp data-end=\"1077\" data-start=\"1053\"\u003eThe dosing unit ensures:\u003c\/p\u003e\n\u003cul data-end=\"1154\" data-start=\"1078\"\u003e\n\u003cli data-end=\"1099\" data-start=\"1078\"\u003e\n\u003cp data-end=\"1099\" data-start=\"1080\"\u003eProper DEF quantity\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-end=\"1123\" data-start=\"1100\"\u003e\n\u003cp data-end=\"1123\" data-start=\"1102\"\u003eCorrect spray pattern\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-end=\"1154\" data-start=\"1124\"\u003e\n\u003cp data-end=\"1154\" data-start=\"1126\"\u003eEven distribution in exhaust\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-end=\"1170\" data-start=\"1156\"\u003eThis prevents:\u003c\/p\u003e\n\u003cul data-end=\"1245\" data-start=\"1171\"\u003e\n\u003cli data-end=\"1192\" data-start=\"1171\"\u003e\n\u003cp data-end=\"1192\" data-start=\"1173\"\u003eDEF crystallization\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-end=\"1210\" data-start=\"1193\"\u003e\n\u003cp data-end=\"1210\" data-start=\"1195\"\u003eCatalyst damage\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-end=\"1245\" data-start=\"1211\"\u003e\n\u003cp data-end=\"1245\" data-start=\"1213\"\u003eInefficient emissions conversion\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-end=\"1280\" data-start=\"1252\"\u003e\u003cstrong\u003e4. Prevent Engine Derate\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp data-end=\"1306\" data-start=\"1281\"\u003eIf the dosing unit fails:\u003c\/p\u003e\n\u003cul data-end=\"1405\" data-start=\"1307\"\u003e\n\u003cli data-end=\"1349\" data-start=\"1307\"\u003e\n\u003cp data-end=\"1349\" data-start=\"1309\"\u003eThe truck may enter power reduction mode\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-end=\"1375\" data-start=\"1350\"\u003e\n\u003cp data-end=\"1375\" data-start=\"1352\"\u003eEmissions faults appear\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-end=\"1405\" data-start=\"1376\"\u003e\n\u003cp data-end=\"1405\" data-start=\"1378\"\u003eThe vehicle may limit speed\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-end=\"1512\" data-start=\"1407\"\u003eThe dosing unit keeps the emissions system functioning correctly so the engine can operate at full power.\u003c\/p\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003cp data-start=\"160\" data-end=\"353\"\u003e\u003cstrong data-start=\"585\" data-end=\"597\"\u003e\u003cbr\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eSigns of a Bad Diesel Exhaust Fluid Dosing Unit A0001405539:\u003cbr\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003ctable width=\"100%\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e\n\u003cp data-start=\"324\" data-end=\"371\"\u003e\u003cstrong\u003e1. Check Engine Light \/ SCR Warning Light\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul data-start=\"372\" data-end=\"462\"\u003e\n\u003cli data-start=\"372\" data-end=\"408\"\u003e\n\u003cp data-start=\"374\" data-end=\"408\"\u003eEmissions system warning appears\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"409\" data-end=\"439\"\u003e\n\u003cp data-start=\"411\" data-end=\"439\"\u003e“SCR System Fault” message\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"440\" data-end=\"462\"\u003e\n\u003cp data-start=\"442\" data-end=\"462\"\u003eDEF system warning\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"464\" data-end=\"495\"\u003eThis is usually the first sign.\u003c\/p\u003e\n\u003cp data-start=\"502\" data-end=\"530\"\u003e\u003cstrong\u003e2. Engine Power Derate\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul data-start=\"531\" data-end=\"644\"\u003e\n\u003cli data-start=\"531\" data-end=\"555\"\u003e\n\u003cp data-start=\"533\" data-end=\"555\"\u003eReduced engine power\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"556\" data-end=\"616\"\u003e\n\u003cp data-start=\"558\" data-end=\"616\"\u003eLimited speed (sometimes 5–55 mph depending on severity)\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"617\" data-end=\"644\"\u003e\n\u003cp data-start=\"619\" data-end=\"644\"\u003e“Engine Derate” message\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"646\" data-end=\"733\"\u003eIf the system can’t control NOx emissions, the truck protects itself by limiting power.\u003c\/p\u003e\n\u003cp data-start=\"740\" data-end=\"776\"\u003e\u003cstrong\u003e3. DEF Crystallization Buildup\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul data-start=\"777\" data-end=\"857\"\u003e\n\u003cli data-start=\"777\" data-end=\"823\"\u003e\n\u003cp data-start=\"779\" data-end=\"823\"\u003eWhite, chalky deposits around the injector\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"824\" data-end=\"857\"\u003e\n\u003cp data-start=\"826\" data-end=\"857\"\u003eDEF residue on exhaust piping\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"859\" data-end=\"877\"\u003eThis may indicate:\u003c\/p\u003e\n\u003cul data-start=\"878\" data-end=\"944\"\u003e\n\u003cli data-start=\"878\" data-end=\"898\"\u003e\n\u003cp data-start=\"880\" data-end=\"898\"\u003eLeaking injector\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"899\" data-end=\"921\"\u003e\n\u003cp data-start=\"901\" data-end=\"921\"\u003ePoor spray pattern\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"922\" data-end=\"944\"\u003e\n\u003cp data-start=\"924\" data-end=\"944\"\u003eStuck dosing valve\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"951\" data-end=\"985\"\u003e\u003cstrong\u003e4. Excessive NOx Fault Codes\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp data-start=\"986\" data-end=\"1022\"\u003eDiagnostic trouble codes related to:\u003c\/p\u003e\n\u003cul data-start=\"1023\" data-end=\"1081\"\u003e\n\u003cli data-start=\"1023\" data-end=\"1041\"\u003e\n\u003cp data-start=\"1025\" data-end=\"1041\"\u003eNOx efficiency\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"1042\" data-end=\"1061\"\u003e\n\u003cp data-start=\"1044\" data-end=\"1061\"\u003eSCR performance\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"1062\" data-end=\"1081\"\u003e\n\u003cp data-start=\"1064\" data-end=\"1081\"\u003eDEF dosing rate\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"1083\" data-end=\"1129\"\u003eThe system detects improper injection amounts.\u003c\/p\u003e\n\u003cp data-start=\"1136\" data-end=\"1169\"\u003e\u003cstrong\u003e5. White Smoke from Exhaust\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul data-start=\"1170\" data-end=\"1229\"\u003e\n\u003cli data-start=\"1170\" data-end=\"1204\"\u003e\n\u003cp data-start=\"1172\" data-end=\"1204\"\u003eVisible white vapor under load\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"1205\" data-end=\"1229\"\u003e\n\u003cp data-start=\"1207\" data-end=\"1229\"\u003eStrong ammonia smell\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"1231\" data-end=\"1250\"\u003eThis can happen if:\u003c\/p\u003e\n\u003cul data-start=\"1251\" data-end=\"1313\"\u003e\n\u003cli data-start=\"1251\" data-end=\"1279\"\u003e\n\u003cp data-start=\"1253\" data-end=\"1279\"\u003eToo much DEF is injected\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"1280\" data-end=\"1313\"\u003e\n\u003cp data-start=\"1282\" data-end=\"1313\"\u003eDEF is not atomizing properly\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"1320\" data-end=\"1346\"\u003e\u003cstrong\u003e6. Poor Fuel Economy\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp data-start=\"1347\" data-end=\"1440\"\u003eImproper emissions control can cause the engine to compensate, slightly affecting efficiency.\u003c\/p\u003e\n\u003cp data-start=\"1447\" data-end=\"1478\"\u003e\u003cstrong\u003e7. DEF Consumption Issues\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul data-start=\"1479\" data-end=\"1540\"\u003e\n\u003cli data-start=\"1479\" data-end=\"1510\"\u003e\n\u003cp data-start=\"1481\" data-end=\"1510\"\u003eDEF level dropping too fast\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"1511\" data-end=\"1540\"\u003e\n\u003cp data-start=\"1513\" data-end=\"1540\"\u003eDEF not being used at all\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"1542\" data-end=\"1583\"\u003eEither can indicate a dosing malfunction.\u003c\/p\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003cp data-start=\"97\" data-end=\"476\"\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan style=\"font-size: 0.875rem;\"\u003eAbout the Manufacturer – \u003c\/span\u003e\u003cspan style=\"font-size: 0.875rem;\"\u003eDetroit Diesel:\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp data-start=\"0\" data-end=\"396\"\u003e\u003cstrong data-start=\"0\" data-end=\"18\"\u003eDetroit Diesel\u003c\/strong\u003e is a leading American manufacturer of \u003cstrong data-start=\"57\" data-end=\"129\" data-is-only-node=\"\"\u003eheavy-duty diesel engines, transmissions, and aftertreatment systems\u003c\/strong\u003e, primarily for the commercial trucking industry. Founded in 1938 and now a subsidiary of \u003cstrong data-start=\"219\" data-end=\"250\"\u003eDaimler Truck North America\u003c\/strong\u003e, Detroit is best known for its \u003cstrong data-start=\"282\" data-end=\"303\"\u003eDD Series engines\u003c\/strong\u003e — including the \u003cstrong data-start=\"320\" data-end=\"344\"\u003eDD13, DD15, and DD16\u003c\/strong\u003e — which power Freightliner and Western Star trucks.\u003c\/p\u003e\n\u003cp data-start=\"398\" data-end=\"791\" data-is-last-node=\"\" data-is-only-node=\"\"\u003eDetroit also produces advanced technologies such as \u003cstrong data-start=\"450\" data-end=\"468\"\u003eDetroit™ Axles\u003c\/strong\u003e, \u003cstrong data-start=\"470\" data-end=\"490\"\u003eDetroit™ Connect\u003c\/strong\u003e telematics, and \u003cstrong data-start=\"507\" data-end=\"533\"\u003eintegrated powertrains\u003c\/strong\u003e, offering fleet operators improved fuel efficiency, uptime, and diagnostics. The company is headquartered in \u003cstrong data-start=\"643\" data-end=\"664\"\u003eDetroit, Michigan\u003c\/strong\u003e, and continues to play a central role in modernizing emissions systems and performance standards in heavy-duty transportation.\u003c\/p\u003e","brand":"Detroit Diesel","offers":[{"title":"Default Title","offer_id":50531898196215,"sku":"A0001405539","price":465.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0895\/7080\/3959\/files\/photo_2026-03-25_19-40-57.jpg?v=1774460555","url":"https:\/\/forcetruckparts.com\/products\/a0001405539-genuine-detroit-diesel%c2%ae-diesel-exhaust-fluid-dosing-unit","provider":"Force Truck Parts","version":"1.0","type":"link"}