{"product_id":"auto-start-stop-eliminator-2025-2026-hyundai-tucson-limited-isg-memory-harness","title":"2025-2026 Hyundai Tucson Limited ISG Eliminator | Memory Harness","description":"\u003cp\u003eThis ISG memory harness is for the 2025–2026 Hyundai Tucson. It stores the last stop-start setting you chose, so if you turned ISG (Idle Stop \u0026amp; Go) off on one drive, it stays off the next time you start the engine. It connects at the ISG button circuit, between the switch and its factory plug.\u003c\/p\u003e\u003cp\u003eYou can still use the original button at any time. Whatever you select last is what the module repeats on the next start. Take the module out and the vehicle behaves exactly as it did from the factory.\u003c\/p\u003e\u003ch2\u003eFitment\u003c\/h2\u003e\u003cp\u003eThis part is listed for these vehicles, all marked 100% fitment match:\u003c\/p\u003e\u003cul\u003e\u003cli\u003eHyundai Tucson: 2025–2026\u003c\/li\u003e\u003c\/ul\u003e\u003cp\u003eThe table does not separate trims; what matters is that the vehicle has factory stop-start and the connector shown in the photos.\u003c\/p\u003e\u003ch2\u003eWhy the button resets\u003c\/h2\u003e\u003cp\u003eISG (Idle Stop \u0026amp; Go) is designed to default to on. The off switch (usually marked with an \"A\" inside a circular arrow) cancels it for the current drive. At the next start the system is armed again. That reset is intentional on the manufacturer's side, and it is the only behavior this module changes.\u003c\/p\u003e\u003ch2\u003eWhat to expect\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eIt remembers the last stop-start setting through a key cycle.\u003c\/li\u003e\n\u003cli\u003eIt leaves the factory button working, so you can turn stop-start back on whenever you want.\u003c\/li\u003e\n\u003cli\u003eIt does not write anything to the vehicle's modules, and removing it restores the stock default.\u003c\/li\u003e\n\u003cli\u003eIt does not change engine power, transmission shifts, emissions calibration or fuel trims.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eA note on the battery\u003c\/h2\u003e\u003cp\u003eThe module draws its power from the vehicle and does not change charging behavior. If your Hyundai Tucson sits for long periods, the same rules apply as without it: a maintainer helps, and a battery that tests weak should be replaced with the type specified for stop-start vehicles (usually AGM or EFB).\u003c\/p\u003e\u003ch2\u003eWhy owners turn it off\u003c\/h2\u003e\u003cp\u003ePressing the same button on every drive is what wears on owners. People who tow, plow, idle in pickup lines, creep through heavy traffic or simply want the engine running at a light end up making the same press dozens of times a week. On the Hyundai Tucson, the module turns that into a one-time choice you can still change whenever you want.\u003c\/p\u003e\u003ch2\u003eInstalling the ISG memory harness\u003c\/h2\u003e\u003cp\u003eIt connects at the ISG button circuit, between the switch and its factory plug. Disconnect nothing else and splice nothing. Once both plugs are locked, tuck the harness where it will not be pinched when the panel goes back on. Test by switching ISG (Idle Stop \u0026amp; Go) off, cycling the ignition and checking the indicator.\u003c\/p\u003e\u003ch2\u003eDiagnostics first\u003c\/h2\u003e\u003cp\u003eA dead or weak battery, a charging problem or an unrelated module fault will change how ISG (Idle Stop \u0026amp; Go) behaves with or without this part installed. Scan the vehicle for stored codes, test the battery and confirm the system works normally with the factory button before installation. That baseline makes any later issue easy to pin down.\u003c\/p\u003e\u003ch2\u003eIf stop-start is not engaging\u003c\/h2\u003e\u003cp\u003eA Hyundai Tucson that rarely auto-stops is often telling you something about the battery. Stop-start vehicles usually run an AGM or EFB battery, and the system is one of the first features to drop out as that battery ages. Cabin temperature requests, engine temperature and brake pressure also factor in. None of these checks are altered by the module.\u003c\/p\u003e\u003ch2\u003eFitment check\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eModel year and model match a row in the table above (2025–2026 Hyundai Tucson).\u003c\/li\u003e\n\u003cli\u003eYour Hyundai Tucson has the factory stop-start button. Base trims or engines without stop-start have nothing for the module to remember.\u003c\/li\u003e\n\u003cli\u003eThe battery and charging system test good and no warning lights are on.\u003c\/li\u003e\n\u003cli\u003eThe connector at your install point matches the one in the product photos.\u003c\/li\u003e\n\u003cli\u003eNo aftermarket remote start, alarm or gateway bypass is wired into the same circuit. If one is, email support before ordering.\u003c\/li\u003e\n\u003cli\u003eIf you are unsure, send your VIN to support@automotivebypass.com and we will confirm fitment.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eEvery listed year\u003c\/h2\u003e\u003cp\u003eOne row per model year, taken from the fitment data for this SKU:\u003c\/p\u003e\u003ctable\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eYear\u003c\/th\u003e\n\u003cth\u003eMake\u003c\/th\u003e\n\u003cth\u003eModel\u003c\/th\u003e\n\u003cth\u003eEngine \/ trim\u003c\/th\u003e\n\u003cth\u003eListing note\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e2025\u003c\/td\u003e\n\u003ctd\u003eHyundai\u003c\/td\u003e\n\u003ctd\u003eTucson\u003c\/td\u003e\n\u003ctd\u003eAll with factory stop-start\u003c\/td\u003e\n\u003ctd\u003e100% Fitment Match | OEM-Grade Quality | Plug \u0026amp; Play\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e2026\u003c\/td\u003e\n\u003ctd\u003eHyundai\u003c\/td\u003e\n\u003ctd\u003eTucson\u003c\/td\u003e\n\u003ctd\u003eAll with factory stop-start\u003c\/td\u003e\n\u003ctd\u003e100% Fitment Match | OEM-Grade Quality | Plug \u0026amp; Play\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003ch2\u003eThe reason the button has to be pressed every trip\u003c\/h2\u003e\u003cp\u003eUS fuel-economy testing explains the reset. If a stop-start system is non-latching, meaning it switches back on whenever the vehicle is restarted, the EPA measures fuel economy with the system working. If the driver can switch it off permanently, the EPA tests with it both on and off and averages the two, which gives a lower number. Manufacturers therefore make the system come back on at every start, and drivers who prefer it off end up pressing the button each trip.\u003c\/p\u003e\u003ch2\u003eCommon questions after fitting\u003c\/h2\u003e\u003cp\u003e\u003cstrong\u003eChoice is forgotten after restart:\u003c\/strong\u003e A plug is usually not fully home. Push each until it latches and test again.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIndicator says the system is unavailable:\u003c\/strong\u003e The vehicle has decided conditions are not right for an automatic stop. This is normal factory behavior.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWarning appears:\u003c\/strong\u003e Remove the module, reconnect the original plug and confirm the warning clears, then contact support.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eEngine keeps shutting off at stops:\u003c\/strong\u003e Switch ISG (Idle Stop \u0026amp; Go) off once. The module stores the off state for the next start.\u003c\/p\u003e\u003ch2\u003eQuick definitions\u003c\/h2\u003e\u003cp\u003e\u003cstrong\u003eNon-latching:\u003c\/strong\u003e A setting that does not stay where the driver left it after a restart.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eKey cycle:\u003c\/strong\u003e One switch-off and restart of the vehicle. Factory stop-start resets at each key cycle.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eAGM \/ EFB battery:\u003c\/strong\u003e Battery types designed for the frequent cycling of stop-start vehicles.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eISG (Idle Stop \u0026amp; Go):\u003c\/strong\u003e Hyundai's name for the automatic engine stop-start feature on the Hyundai Tucson.\u003c\/p\u003e\u003ch2\u003eBefore you plug it in\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eIgnition off, transmission in Park, fob outside the cabin.\u003c\/li\u003e\n\u003cli\u003eInstructions for your exact model at hand.\u003c\/li\u003e\n\u003cli\u003eConnector location confirmed against the photos before any panel comes off.\u003c\/li\u003e\n\u003cli\u003eA plastic pry tool for clips, if the connector sits behind trim.\u003c\/li\u003e\n\u003cli\u003eBoth connector locks fully engaged after fitting.\u003c\/li\u003e\n\u003cli\u003eModule and lead fixed in place, clear of pedals, steering and heat.\u003c\/li\u003e\n\u003cli\u003eTest: choose your ISG (Idle Stop \u0026amp; Go) setting, turn the vehicle off, restart and check the indicator.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eBattery and starter on stop-start vehicles\u003c\/h2\u003e\u003cp\u003eStop-start puts extra load on the battery and starter, so manufacturers fit an AGM or enhanced flooded (EFB) battery and a starter rated for more cycles. Battery state is one of the inputs that decides whether the engine may stop. With the module installed the same rules apply, and the same battery type should be used when it is replaced.\u003c\/p\u003e\u003ch2\u003eQuestions owners ask\u003c\/h2\u003e\u003ch3\u003eHow does it connect?\u003c\/h3\u003e\u003cp\u003eIt connects at the ISG button circuit, between the switch and its factory plug.\u003c\/p\u003e\u003ch3\u003eWill ISG (Idle Stop \u0026amp; Go) come back on when I restart my Hyundai Tucson?\u003c\/h3\u003e\u003cp\u003eNot if you turned it off before shutting down. The module repeats your last selection at the next start. If you leave it on, it stays on.\u003c\/p\u003e\u003ch3\u003eWhich Hyundai Tucson years does this fit?\u003c\/h3\u003e\u003cp\u003eThe listed range is 2025–2026. Check the fitment table on this page against your exact model year.\u003c\/p\u003e\u003ch3\u003eWhy does my Hyundai Tucson sometimes not auto-stop even when the system is on?\u003c\/h3\u003e\u003cp\u003eThe factory logic checks battery charge, engine temperature, climate load and other inputs. If any are outside range it keeps the engine running. The module does not affect those checks.\u003c\/p\u003e\u003ch3\u003eWhy does ISG (Idle Stop \u0026amp; Go) turn itself back on every time?\u003c\/h3\u003e\u003cp\u003eAutomakers set stop-start to default to on at each start. Under EPA test rules, a system that stays off after shutdown is tested both on and off and the results are averaged, which lowers the rated fuel economy, so most systems reset at every key cycle. The module carries your last choice across that reset.\u003c\/p\u003e\u003ch3\u003eWhat happens if I unplug it?\u003c\/h3\u003e\u003cp\u003eThe vehicle returns to the factory default, with ISG (Idle Stop \u0026amp; Go) switched on at every start.\u003c\/p\u003e\u003ch3\u003eWill it fix a \"stop-start unavailable\" message?\u003c\/h3\u003e\u003cp\u003eNo. That message usually points to the battery or a sensor. Diagnose and repair that first.\u003c\/p\u003e\u003ch3\u003eCan I remove it later?\u003c\/h3\u003e\u003cp\u003eYes. Unplug the module and reconnect the factory connector; the vehicle returns to its stock default.\u003c\/p\u003e\u003ch3\u003eDoes it change how the battery is charged?\u003c\/h3\u003e\u003cp\u003eNo. Charging is still managed by the vehicle. Stop-start vehicles normally use an AGM or EFB battery built for frequent restarts; replace it with the same type when it wears out.\u003c\/p\u003e\u003ch3\u003eDoes the stop-start button still work after installation on the Hyundai Tucson?\u003c\/h3\u003e\u003cp\u003eYes. The factory button works normally. The module simply stores whatever you chose last.\u003c\/p\u003e\u003ch3\u003eIs this the same part for every Hyundai?\u003c\/h3\u003e\u003cp\u003eNo. Connectors and the module that holds the stop-start state differ by platform, so this SKU is matched to the fitment rows on this page. Send the VIN to support if you are unsure.\u003c\/p\u003e\u003ch3\u003eDoes my Hyundai Tucson need the factory stop-start button for this to work?\u003c\/h3\u003e\u003cp\u003eYes. The module works with the factory stop-start system and its button. A vehicle built without stop-start has no setting for it to remember.\u003c\/p\u003e\u003ch3\u003eDoes it change engine power or fuel trims?\u003c\/h3\u003e\u003cp\u003eNo. It does not reprogram the engine or transmission computers. It only stores the stop-start button state.\u003c\/p\u003e\u003ch2\u003eShipping and support\u003c\/h2\u003e\u003cp\u003eShipping is free to the contiguous US. Orders leave in 1–2 business days and usually arrive 3–4 business days later. Returns are accepted within 45 days with pre-approval; a 20% restocking fee applies and the buyer covers return shipping. The part carries a 3-year limited warranty, and support@automotivebypass.com answers Monday to Friday, 9–5 Pacific.\u003c\/p\u003e","brand":"Automotivebypass","offers":[{"title":"Default Title","offer_id":56493813662068,"sku":"RC-ASSE-46-01","price":89.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1030\/8439\/2820\/files\/2025-2026_Hyundai_Tucson_Limited_Auto_Start-Stop_Eliminators_1.jpg?v=1793348080","url":"https:\/\/automotivebypass.com\/products\/auto-start-stop-eliminator-2025-2026-hyundai-tucson-limited-isg-memory-harness","provider":"Automotivebypass","version":"1.0","type":"link"}