These instructions apply to the Kia Sorento Mk4 (MQ4) 2020-Present.
For other models, please choose your vehicle here.
The Kia Sorento Mk4 (MQ4, 2020–present) has an Idle Stop & Go (ISG) system that switches the engine off at a standstill to save fuel and reduce emissions, then restarts it as you lift off the brake or dip the clutch. The brief shudder as the engine dies at a junction is ISG working normally, not a fault. Many owners still prefer to keep the engine running — in slow traffic, on a very hot or cold day, or before working in the engine bay — and you switch it off with one button. (Hybrid Sorentos manage the engine automatically and don’t use a conventional ISG button.)
How ISG Works on the Sorento
Idle Stop & Go only shuts the engine down when a range of conditions is satisfied: the car is fully stopped, the brake is firmly held (or on a manual, the gearbox is in neutral with the clutch up), the 12 V battery has good charge, and the engine and cabin are close to temperature. A battery sensor watches state of charge continuously, so ISG holds off whenever a stop would leave too little reserve for a clean restart. Because so much rides on that battery, keeping it healthy is the biggest single factor in ISG behaving the way you expect.
Before You Begin
- The engine should be running — the button toggles the current drive, not a stored setting.
- Do it stationary, in Park or neutral, not while moving.
- Locate the ‘A OFF’ (ISG) button near the steering wheel or switch bank before you set off.
- About to open the bonnet? Switch ISG off first so the engine can’t restart unexpectedly.
How to Turn Off Idle Stop & Go
- Find the ‘A OFF’ (ISG) button on the dashboard, usually near the steering wheel or switch bank.
- Press it once — the indicator confirms ISG is off, and the engine will keep running when you stop.
It Resets Every Drive
Like nearly every car with this feature, the Sorento re-enables ISG each time you switch the ignition off and on. There’s no permanent factory ‘off’ — press the button once per journey if you don’t want it.
Why Switch It Off?
- Before engine-bay work — stops an unexpected restart.
- Stop-go traffic — avoids constant restarts.
- Maximum cabin cooling/heating on extreme days.
ISG also won’t stop the engine on its own when the battery is low, the cabin is still heating/cooling, or the engine is cold — that’s normal.
If the Engine Won’t Cut Out
If ISG has stopped shutting the engine off and you haven’t pressed the button, work through the common reasons before assuming there is a fault:
- Weak or ageing 12 V battery — the most common cause; ISG suspends itself to protect the charge needed for a restart.
- Cold start — on a cold morning the engine and catalytic converter must warm up before a stop is allowed.
- Cabin climate demand — with the heater or air-con working hard, the engine stays on to hold the temperature.
- Brake not firmly held, or on a manual the clutch not fully up in neutral.
- Steep gradient or the Sorento not fully at rest — a stop may be inhibited on a slope.
- Recent battery disconnect — the charge sensor relearns over a few normal drives before it trusts a stop.
- Bonnet or door open, belt unbuckled — interlocks keep the engine running.
After the Reset
Once you press the button the indicator changes to show ISG is off, and the engine idles normally at every stop for the rest of that journey. Nothing else changes — there is no warning light and no stored fault. The next time you start the Sorento, ISG comes back on automatically, so if you consistently dislike it, make pressing the button part of your setting-off routine.
Frequently Asked Questions
How do I turn off auto stop/start on a Kia Sorento?
With the engine running, press the A OFF (ISG) button near the steering wheel or switch bank. The indicator confirms Idle Stop & Go is off and the engine will idle at every stop. The setting only lasts for the current journey.
Can I disable ISG permanently?
No — the Sorento resets Idle Stop & Go to on at every ignition cycle by design, so there is no dashboard toggle that stays off. The simplest approach is to press the button once each drive whenever you would rather the engine kept running.
Why did ISG come back on?
Switching the ignition off and on re-enables it automatically — it does not turn itself back on while you drive. If you stopped and restarted the engine, the default returned, so you will need to press the button again for the next leg of the trip.
Why won’t the engine stop sometimes?
A low or ageing 12 V battery, a cold engine, or the cabin still reaching temperature will all hold the engine running with ISG on. That is deliberate protection, not a fault. Once the car is warm and the battery well charged, normal stops usually resume.
Is leaving ISG on bad for the engine?
No. The Sorento’s starter, battery and engine are all designed for frequent restarts, so leaving ISG on causes no extra wear. Switching it off is purely a comfort choice — both settings are equally safe to use every day.
Does the hybrid Sorento have an ISG button?
The self-charging and plug-in hybrid Sorento manage the petrol engine automatically as part of normal hybrid operation, so the engine starting and stopping is expected and is not controlled by a conventional A OFF button. This guide applies to the non-hybrid Sorento with the ISG switch.
If an ISG fault light shows instead of the normal indicator, look it up on autodtcs.com — a tired 12 V battery is the usual cause. See our Sorento battery guide.
Independent guide — not affiliated with Kia. Always follow your official service manual and safety precautions. Read our full disclaimer.