Piston Slap: Putting the Brakes on Auto Start/Stop?
Hagerty Community member HelenC writes:
Sajeev, my question is how do you disable the stop/start feature on a Jeep Grand Cherokee? It would be a tremendous service to your readers if you explained how to do it on not only Jeep products but GM and Ford.
I know the car companies have not come up with such an iterative feature since they put those seat belt starter interlocks on cars back in 1974. However it was easy to disable by just cutting all the wires under the seat. This aggravation may be more complicated to find which wires to cut so all your help would be appreciated.
Sajeev answers:
Turns out I got this one wrong, as there are modules that defeat this system. But remember these can void your vehicle’s warranty, so let the buyer beware.
Before I reply, please permit me to weasel out of a proper answer. Because getting a representative vehicle from all manufacturers, performing the task (either manually or electronically) to verify for myself, and then subsequently getting banned from all media fleets would kinda tank (what’s left of) my career as an automotive journalist. I’m only kinda joking, as doing this on not-media fleet vehicles would also be too cost prohibitive. And with that out of the way…
Let me instead point you in the right direction to disable auto start/stop in your vehicle. And this “pointing” is more valuable over time, as vehicle systems change over time, but the people who work on them generally do not.
- Call or email ECU tuners (Ford, GM, Chrysler) to see if they can remove auto start/stop from their software. This is often possible, but only they will know as they have access to the software and the ability to do what you want.
- Ask a dealership’s service department if start/stop can be removed either with their software, or unplugging/bypassing a wiring harness. (I assume the answer will be no, but it never hurts to ask.)
- Find out who makes the start/stop starter unit in your application. (Denso is a well known brand in this space.) Once you know the brand you can see what inputs it takes from the rest of the car to operate. Maybe you can disable start/stop without destroying the rest of the starter.
My advice tries to cover all bases, but honestly, you only need the first option. An ECU tuner will know more than anyone else, as modern cars use multiplex wiring that ensures any physical modification will take out more things than just the start/stop feature.
I suspect a tuner can make the system default to “off” so you can hit the button and turn it on if you tire of getting 0 MPG in traffic. Problem is, the tuner’s work isn’t free. It will cost hundreds of dollars, but it’s worth it if you also load a tune that allows for more power (premium fuel sometimes required), eliminate the throttle/torque management software, and firm up the transmission shifts.
Almost all of my EFI-powered vehicles have been tuned by a professional in the aftermarket, and I recommend it for more reasons than just disabling a start/stop feature. But that should get you exactly what you need, no matter what make or model we are discussing.
(For the record, I have no problem with this feature in late model vehicles. Times have changed, its operation is relatively seamless, and eliminating periods of 0 MPG when stuck in suburban sprawl has financial and ecological merit.)
Have a question you’d like answered on Piston Slap? Send your queries to pistonslap@hagerty.com—give us as much detail as possible so we can help! Keep in mind this is a weekly column, so if you need an expedited answer, please tell me in your email.
_(cropped).jpg){kind=link}
You can do it at home with the alfaobd app. You can also activate or disable a lot of other things as well. Alfaobd is less than $50 – you may be able to do it with the trial version, but if not it’s around thirty five dollars and takes ten minutes of time. Have a great day
Search auto stop start eliminator. I bought a device for $120 that plugs in under the drivers seat of my 22 Jeep Grand Cherokee. Installs in 60 seconds and works like a charm.
For my VW you can buy a cable that emulates start/stop deactivation button press each time you start the car. It stores last set position so you can either have it on or off as you please. Installation wit YT instructions takes minutes and it works flawlessly without changing any of the car’s software that may be harmful to the car (in VW it actually is due to change of some voltage/charging parameters).
Maybe sth similar is available for other cars with physical S&S buttons.
I have used this product on few vehicles and works really well.
Highly recommend it. https://www.autostopeliminator.com/?gad_source=1&gclid=Cj0KCQjw-5y1BhC-ARIsAAM_oKmPEExgkuTel-NzsknWSBZ5ADxQtVdspLsr1akSVlaRBYb2voVzUK8aAi_sEALw_wcB
Yes, just like another corporate vs. consumer problem product….we want results not levy for an issue that we paid for already ., just fix it…then ask for the money.. Mr. CEO
A company called Autostop Eliminator makes a module for a lot of cars. I paid $100 for a module for my 23 Tahoe. There is a 3 minute video for installation and it took me 15 minutes to install. It doesn’t disable the feature, it just allows the car to stay in the last position when you restart. Now I don’t have to turn it off every freaking time. Or worse, sit through the constant stops when my wife drives and doesn’t press the off button. Life changer.
You people are missing critical areas. The thought was good enough. Reduce emissions. BUT the mechanical harm it does to the engine, transmission and starter is the problem they haven’t worked out, it can’t obviously. If the dealers would replace those parts free of charge when using it then that’s one thing, but you know that ain’t gonna happen. Prematurely replacing a motor or tranny is no joke
As a guy who grew up driving old MGs and Triumphs, whose electrical components all seemed to lead very finite and undependable lives, the auto-start stop feature on our new Subaru feature was a bit disconcerting. Am I wearing out the starter? Will it start again? Will the battery go flat? I realize it is new and designed to work this way, but that doesn’t always mean seemless and reliable.
Anyway, we used to turn it off, but have kind of gotten used to it. I don’t worry about it so much anymore, but the Subaru is not exactly the smoothest starting vehicle. It kind of gives a rattle and shake like an old tractor when you start it up.
Sure you get 0mpg with the engine off… but its horrible for the wear of components to constantly turn the engine on and off, also not better for the environment so there is absolutely no reason for it to exist
On my 2019 Toyota Highlander, if I don’t push the brake pedal hard when stopping, the engine won’t shut off. Also, if it has stopped, if I ease up the pressure on the brake pedal, it will restart and stay on. I’ve never really looked into disabling it.
Exactly the same for my 2020 GTI. A mechanic friend told me that start stop usually is activated by the brake line pressure, not a switch.
Apart from a lot more wear on the flywheel ring gear, excessive starting and stopping will wear the timing chain and guides. Heavy duty starters and batteries are normally fitted but other parts are not intended to be frequently used in this way.
Our new 2023 Traverse i got a $20-$30 device off Amazon which mounts near hood latch, it deactivated the pesky start stop and extended engine life components.
Buy a manual transmission, no stop/start.
My Subaru has a button, you do have to manually turn it off each time you start the car.
Believe it or not, but I have seen manual transmission BMWs with this feature! (But that was 8-10 years ago.)
With my Kia it was simple, the button on the dash had to be pushed on restart every time so I just jammed it in with a peace of plastic.
The 2019 Grand Cherokee had poor auxiliary batteries. Once that battery dies (mine has) auto stop/start doesn’t work. You get a “battery charging” message