{"product_id":"18-5461-genuine-mercury-mercruiser®-ignition-control-module","title":"18-5461 | Genuine Mercury MerCruiser® Ignition Control Module","description":"\u003cdiv class=\"ftp-desc\"\u003e\n\u003cp\u003eAn Ignition Control Module (ICM)\u003cstrong\u003e 18-5461 \u003c\/strong\u003eis an electronic component in a gasoline-powered vehicle that controls when the spark plugs fire. Its job is to make sure the spark happens at precisely the right moment so the engine runs smoothly.\u003c\/p\u003e\n\u003ch3\u003eGeneral Specifications\u003c\/h3\u003e\n\u003cdiv class=\"ftp-table-wrap\"\u003e\u003ctable class=\"ftp-spec\"\u003e\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eCondition\u003c\/th\u003e\n\u003ctd\u003eNew\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003ePart Number\u003c\/th\u003e\n\u003ctd\u003e18-5461\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth scope=\"row\"\u003eBrand\u003c\/th\u003e\n\u003ctd\u003eMercury MerCruiser\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\u003c\/table\u003e\u003c\/div\u003e\n\u003ch3\u003eFitment\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMerCruiser 4.3L, 5.0L, 5.7L, 7.4L Bravo Gen+\u003c\/strong\u003e (Thunderbolt V ignition)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCarb Alpha\/Bravo\u003c\/strong\u003e models across multiple serial number ranges from \u003cstrong\u003e0M600000 and newer\u003c\/strong\u003e, including later production.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003ePurpose \u0026amp; Function\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eControls spark timing\u003c\/strong\u003e\n\u003cul\u003e\n\u003cli\u003eIt determines when the ignition coil should fire, sending a spark to the spark plugs at the correct point in the engine's cycle.\u003c\/li\u003e\n\u003cli\u003eProper timing improves power, fuel economy, and emissions.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOperates the ignition coil\u003c\/strong\u003e\n\u003cul\u003e\n\u003cli\u003eThe ICM switches the ignition coil on and off, allowing it to build up and release the high voltage needed to create a spark.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHelps start the engine\u003c\/strong\u003e\n\u003cul\u003e\n\u003cli\u003eDuring cranking, the ICM ensures the spark plugs receive sparks at the correct intervals so the engine can start.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWorks with the engine computer\u003c\/strong\u003e\n\u003cul\u003e\n\u003cli\u003eIn many vehicles, the ICM communicates with the engine control module (ECM), which adjusts ignition timing based on engine speed, load, temperature, and other sensor inputs.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProtects the ignition system\u003c\/strong\u003e\n\u003cul\u003e\n\u003cli\u003eSome ICMs include features that prevent damage to the ignition coil by controlling how long current flows through it.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eSigns of a Bad Ignition Control Module\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eEngine won't start\u003c\/strong\u003e\n\u003cul\u003e\n\u003cli\u003eThe engine may crank normally but never start because the spark plugs aren't receiving a spark.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIntermittent stalling\u003c\/strong\u003e\n\u003cul\u003e\n\u003cli\u003eThe engine may suddenly shut off while driving, then restart after it cools down. This is a classic symptom of an ICM that is failing from heat.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMisfiring\u003c\/strong\u003e\n\u003cul\u003e\n\u003cli\u003eOne or more cylinders may not fire correctly, causing the engine to run rough.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRough idle\u003c\/strong\u003e\n\u003cul\u003e\n\u003cli\u003eThe engine may shake or idle unevenly due to inconsistent spark timing.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePoor acceleration\u003c\/strong\u003e\n\u003cul\u003e\n\u003cli\u003eThe vehicle may hesitate or lack power when you press the accelerator.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEngine hesitation or bucking\u003c\/strong\u003e\n\u003cul\u003e\n\u003cli\u003eThe engine may stumble, jerk, or surge while driving.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCheck Engine Light\u003c\/strong\u003e\n\u003cul\u003e\n\u003cli\u003eMany vehicles will illuminate the Check Engine Light if the ECM detects ignition-related problems.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eReduced fuel economy\u003c\/strong\u003e\n\u003cul\u003e\n\u003cli\u003eImproper ignition timing can cause incomplete combustion, increasing fuel consumption.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEngine dies after warming up\u003c\/strong\u003e\n\u003cul\u003e\n\u003cli\u003eSome ICMs work when cold but fail once they heat up, causing the engine to stall after several minutes of driving.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eAbout Mercury MerCruiser\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eMercury MerCruiser\u003c\/strong\u003e is a leading marine engine brand known for its reliable, high-performance inboard and sterndrive power systems. Built by Mercury Marine, MerCruiser engines are widely used in recreational boats for their strong acceleration, smooth operation, and durability. The brand is recognized for combining advanced engineering with easy maintenance, making it a popular choice among boaters and manufacturers worldwide.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"Mercury MerCruiser","offers":[{"title":"Default Title","offer_id":51006279516407,"sku":"18-5461","price":599.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0895\/7080\/3959\/files\/photo_2026-08-21_06-28-21.jpg?v=1787283018","url":"https:\/\/forcetruckparts.com\/products\/18-5461-genuine-mercury-mercruiser%c2%ae-ignition-control-module","provider":"Force Truck Parts","version":"1.0","type":"link"}