I have a Jeep Cherokee and it has the "Start-Stop" feature which I find very annoying
and of little to no value to me. I know it can be turned off but you must do it each time
you restart the vehicle.

For those not familiar, this is supposed to be a gas saving
feature where the engine shuts off every time you stop the vehicle and restarts when
you remove your foot from the brake. I won't go into more right now about my thoughts
about this but I would like to know if anyone can figure out how this company has
designed a device that plugs into the diagnostic port to safely defeat this annoying
feature. I came across this web page so if interested, take a look at it :
smartstopstart.com

Does anyone think it would be possible to make your own device that does what this
device does?..... trying to save a few bucks. I doubt that it is as simple as a couple
of jumper wires ... likely an active circuit of some type.

Thanks for any input.

 

Any CAN bus capable controller could do the job. It would just send a message to the engine controller that the button was pressed. The trick would be knowing the proper sequences for the controller.

 

You could probably add a 555 timer circuit and a relay across the push button contacts that automatically simulates a button-push after you start the vehicle.

 

Drive with the driver door open, hood up, or A/C on max...

 

 

Drive with the driver door open, hood up, or A/C on max...

I had this on the minivan (2017 Chrysler Pacifica) I rented for my summer Vegas trip. It takes 2 seconds to press the button after pressing the button to start the car. People are hyper if that's too much effort. It's easy to defeat with a slow 'California' stop and move forward.

 

I rented an Audi in Holland did the same thing. I agree it is very annoying.

One thing that you could do is get a can bus sniffer and see what messages come across whenever you disable the ESS from the dash, and then programming Arduino or something to replicate the same messages every time you turn the car on.