{"product_id":"def-idle-air-control-valve-motor-iac-for-mercruiser-ecm-555-2001-sierra-18-7701-862998-direct-replacement-with-gasket","title":"DEF Idle Air Control Valve Motor IAC for MerCruiser ECM 555 (2001+) — Sierra 18-7701 \/ 862998 Direct Replacement with Gasket","description":"\u003cp\u003e\u003cstrong\u003eDEF Idle Air Control Valve (IAC) 862998 \/ Sierra 18-7701 is a direct-replacement idle air control motor engineered to fit MerCruiser ECM 555 (2001+) and a wide range of Alpha and Bravo engines.\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThis replacement IAC motor from DEF restores precise idle airflow control on compatible MerCruiser powerheads. Built as a brand-new, high-quality unit, it comes with the required gasket and is intended to match the fit and function of original OE components for applications listed by Sierra part 18-7701 and MerCruiser part 862998.\u003c\/p\u003e\n\n\u003ch3\u003eWhich engines and ECMs will this IAC motor fit?\u003c\/h3\u003e\n\u003cp\u003eThis DEF IAC motor is designed for MerCruiser ECM 555 models from 2001 onward and fits many Alpha and Bravo models. It covers a variety of displacements and induction systems for broad compatibility.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eCompatible with MerCruiser ECM 555 (2001+)\u003c\/li\u003e\n  \u003cli\u003eFits Alpha 4.3L and Bravo 5.0L\/5.0LX models\u003c\/li\u003e\n  \u003cli\u003eWorks with 5.7L 350 MAG, 5.7L Bravo EFI, and 454\/502\/7.4L\/8.2L MPI\/MIE engines\u003c\/li\u003e\n  \u003cli\u003eDirect replacement for Sierra 18-7701 and MerCruiser 862998\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eHow does installing this replacement IAC motor affect idle performance?\u003c\/h3\u003e\n\u003cp\u003eReplacing a worn or faulty IAC motor with this DEF unit helps restore steady idle control by regulating the airflow bypassing the throttle plate. Expect smoother idle transitions and more reliable engine speed management when the part matches the engine’s requirements.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eRe-establishes consistent idle airflow regulation\u003c\/li\u003e\n  \u003cli\u003eReduces hunting or unstable idle behavior\u003c\/li\u003e\n  \u003cli\u003eSupports correct idle recovery after load changes\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat comes in the box and what should I prepare for installation?\u003c\/h3\u003e\n\u003cp\u003eThe product ships as a single IAC valve motor with a new gasket to ensure a proper seal during installation. Basic hand tools and a clean mounting surface are typically all that’s needed; follow manufacturer torque specs and electrical connector polarity when reattaching.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003e1 × DEF Idle Air Control Valve motor\u003c\/li\u003e\n  \u003cli\u003e1 × replacement gasket included\u003c\/li\u003e\n  \u003cli\u003ePrepare screwdrivers, socket set, and cleaner for mating surfaces\u003c\/li\u003e\n  \u003cli\u003eVerify connector pin alignment and ECM compatibility before installation\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWill this DEF part meet OEM fit and durability expectations?\u003c\/h3\u003e\n\u003cp\u003eThis unit is produced as a high-quality aftermarket replacement intended to replicate OEM fit and basic durability for the listed applications. It’s made for direct swap-in where the original part numbers Sierra 18-7701 or MerCruiser 862998 are specified.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eManufactured as a brand-new replacement component\u003c\/li\u003e\n  \u003cli\u003eEngineered to match mounting points and electrical interface\u003c\/li\u003e\n  \u003cli\u003eIncludes gasket to help prevent vacuum or coolant leaks at the mount\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eWho is this for: Technicians, boat owners, and marine service shops replacing a failing idle air control motor on MerCruiser engines that use ECM 555 (2001 and newer) will find this DEF IAC valve useful. Choose this unit when you need a direct-fit aftermarket alternative to Sierra 18-7701 or MerCruiser 862998 that ships ready for installation with a gasket and aims to restore proper idle regulation.\u003c\/p\u003e\n\u003csection class=\"product-faq-snippet\"\u003e\u003ch3\u003eFAQ\u003c\/h3\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Is this DEF IAC the same as MerCruiser 862998?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Yes. This DEF unit is a direct replacement compatible with MerCruiser part 862998 and Sierra 18-7701.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Does it include the gasket for installation?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Yes. The IAC motor ships with one gasket to ensure a proper seal at installation.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/section\u003e","brand":"DEF","offers":[{"title":"Default Title","offer_id":48084859617438,"sku":"B07RXQBV4Y","price":40.98,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0781\/2041\/9486\/files\/def-iac-front-view.jpg?v=1785864122","url":"https:\/\/northtrailauto.ca\/products\/def-idle-air-control-valve-motor-iac-for-mercruiser-ecm-555-2001-sierra-18-7701-862998-direct-replacement-with-gasket","provider":"North Trail Auto","version":"1.0","type":"link"}