Disable Mazda i-stop: Per-Drive Button or FORScan Coding

i-stop is Mazda’s auto start-stop: it cuts the engine when you brake to a standstill and restarts it when you lift off, to save fuel at idle. Two ways switch it off, and they are not the same job. The dash i-stop OFF button disables it for the current drive only and resets to ON every time you start the engine. A permanent disable means changing one bit in the car’s AS-Built data with FORScan, reprogramming at a dealer, or an aftermarket plug-in module. Pick by how often you want to press a button.

The short answer

Method	What it does	Persists across restarts?	Verdict
Dash i-stop OFF button	Disables i-stop for this drive	No, resets ON at next engine start	Use it if pressing one button per drive is fine
FORScan AS-Built coding (SSU module)	Clears the i-stop enable bit	Yes, stays off	The clean permanent fix on non-MHEV SkyActiv cars
Dealer reprogram (Mazda MDS)	Software adjustment at the dealer	Yes	Costs shop time; rarely worth it over FORScan
Aftermarket disabler module	Auto-presses the button each start	Yes, by faking the press every time	Cheap ($20–$80) and reversible, but it is a hack

There is no factory menu setting that keeps i-stop off; Mazda designed the system to default ON with every ignition cycle (aautomotives).

The dash button: one press, off until the next start

The fastest way to silence i-stop for a drive is the dedicated OFF switch. Press it once, hold until the beep sounds, and the amber i-stop indicator in the instrument cluster lights to confirm the system is off (Mazda3 owner’s manual). Press it again to turn i-stop back on. The button icon is a circle containing an “A” and a circular arrow; when off, the cluster shows that same i-stop symbol with a slash through it (ok.com).

The catch is in the manual, quoted directly: “If the i-stop function was turned off using the i-stop OFF switch, the system will resume operation the next time the engine is started” (Mazda3 owner’s manual). The same section exists in the Mazda2 manual, so this is generic Mazda i-stop behavior, not one model’s quirk. The button is a per-drive override.

Button location varies by model (aautomotives):

• CX-5 (2017–2025). Center console, near the hazard-light button.
• Mazda3 (2019–2025). Center console, left of the gear selector.
• CX-30 (2020–2025). Lower dash, driver’s side.
• Mazda6 (2014–2023). Dash, near the steering wheel.

Some markets and JDM-spec cars place the switch lower-left, below the wheel and above the brake pedal (ok.com). One JDM-spec owner reports their dash button toggles i-stop permanently rather than per-drive, so market firmware differs (owner-reported, r/CX5).

Owners also report a braking trick that avoids the button: brake firmly to a complete stop, then ease pressure off the pedal slightly without letting the car roll. i-stop only cuts the engine when you hold the brake hard at a standstill (owner-reported, r/CX5).

FORScan: clear one bit and i-stop stays off

The permanent fix on non-hybrid SkyActiv cars is an AS-Built coding change with FORScan and an OBD-II adapter. The relevant module is the SSU, AS-Built address line 731-01-01. i-stop is governed by one bit: byte B1, bit b4, where 1 is i-stop ON and 0 is i-stop OFF. Clear that bit and the system stays off across every drive cycle (FORScan forum t=3379).

On the example car in that thread the line reads 1014 E024 2082, and disabling i-stop changes it to 1004 E024 2072 (FORScan forum t=3379). A 2016 Mazda2 1.5D owner confirmed the identical procedure: SSU module, line 731-01-01, flip bit B1 b4 from 1 to 0 (FORScan forum t=18179). The exact hex differs from car to car, so read your own line first and clear bit b4 of B1 rather than copying a forum string.

Steps:

1. Back up first. Save the SSU module’s original AS-Built read-out before you change anything, so you can write it back. See AS-Built backup and restore. This step turns a mistake into a non-event.
2. Read the line. Open the SSU module, line 731-01-01, and note the current value of byte B1.
3. Clear the bit. Clear bit b4 of byte B1. In the thread’s example that takes 1014 E024 2082 to 1004 E024 2072. Match the change to your own read value, not the example.
4. Write the value. Write the new value to the SSU and cycle the ignition. i-stop now stays off; the amber OFF indicator no longer needs a button press each drive.

This is reported working on the Mazda6 (2014 and up), CX-5, and Mazda2 1.5D (FORScan forum t=3379, t=18179). It is the same single-bit AS-Built technique used to kill Ford auto start-stop, but the Ford address is a different module (BCM 726-48-02) and must not be used on a Mazda (FORScan forum t=3218).

The other permanent routes: dealer software or a plug-in module

Two non-FORScan options exist for owners who do not want to code their own car (aautomotives, ok.com):

• Dealer reprogram. Via Mazda MDS, a dealer adjusts the setting with Mazda’s diagnostic system. It works, but it is shop time you pay for, and FORScan does the same job at home.
• Aftermarket disabler module. A $20–$80 plug-in device that intercepts the OFF button and presses it at every start, so the car boots with i-stop already off. It fakes the per-drive press rather than changing coding, and unplugs to reverse.

i-stop needs an EFB battery, and a weak one disables it for you

i-stop deep-cycles the battery through every stoplight restart, so these cars need an enhanced flooded battery (EFB), commonly the Q85 / D23 size, not an ordinary flooded battery. EFBs use thicker lead plates built for frequent start-stop cycling and deeper discharge (FastFix, FastFix Q85). Fit a wrong or weak battery and i-stop simply stops working. Owners report roughly $400 for the OEM battery from a Mazda dealer, about twice the ~$200 of a comparable aftermarket AGM (owner-reported, Mazda3 Forum). Full sizing and swap detail is in battery replacement.

i-stop also disables itself automatically. It will not engage when battery charge is low, when the engine is not yet at operating temperature, under high A/C demand, or on a steep incline (rollback protection) (aautomotives). Owners treat the most common case as a diagnostic: when i-stop quits engaging on its own and the amber light stays lit, the battery is usually weak or aging (owner-reported, r/mazda6, r/CX5).

Less cycling means less battery wear, which is why many owners turn it off. One Mazda6 owner estimates disabling i-stop in heavy stop-and-go adds about two years of battery life, and a CX-90 mild-hybrid owner doing short town trips says permanently disabling it ended their recurring low-battery warnings (owner-reported, r/mazda).

Which Mazdas have i-stop, and which can be coded off

i-stop spans the SkyActiv lineup: Mazda2, Mazda3, Mazda6, CX-3, CX-5, MX-5/Miata, and the RX-8 (FastFix Q85). The CX-30 (2020–2025) has it too, going by its documented OFF-button location (aautomotives), as do the newer CX-60/70/80/90 mild hybrids (r/mazda). Whether a specific car has it depends on year, trim, and market. Notably, many CX-5s built during the chip shortage shipped without i-stop at all (owner-reported, r/CX5).

Two caveats on the permanent disable:

• Mild hybrids. Different hardware. On the CX-60/70/80/90 an Integrated Starter-Generator (ISG) restarts the engine, which makes restarts smoother but also means the SSU 731-01-01 method above is documented for older non-MHEV SkyActiv cars and may not map to MHEV models (owner-reported mechanism, r/mazda).
• Cylinder deactivation. A separate system. Mazda’s cylinder-deactivation tech arrived in the US for 2018 (CX-5 and Mazda6); a car may have one, both, or neither (Sport Mazda). Disabling i-stop does not touch it.

Related

• Battery replacement: the EFB/Q85 spec, why i-stop cars need it, and the BMS reset
• FORScan overview: what FORScan is and the adapter you need
• AS-Built backup and restore: save the SSU data before coding