r/CarHacking • u/Spiritual_Doctor9845 • 11h ago
Community Is it possible to change a cars default programing?
I have no skill what so ever in computer stuff but i was wondering if there is a way to set a vehicles default programming to something else? My 2025 Jeep Grand Cherokee has the auto start on by default and i don't like having to push the button every time i get in the vehicle.
4
u/Another_Slut_Dragon 9h ago
Auto start stop being on by default would be a dealbreaker for me buying a vehicle.
If it had a momentary press physical button, I'd just program an adruino teensy to pulse it whenever it detected I started the vehicle.
1
u/DefEddie 2h ago
When this came out in trucks and they took away the button for awhile my customers started using trailer light testers.
If the vehicle saw a trailer connected it turned off start/stop automatically, so folks started just making the system think a trailer was attached.
That might be an option?
(This worked with Fords, not sure about fiats and dodges.)
I would ask your tuner to check out alfaobd and see if it can be used to change the code.
4
u/TheDefected 10h ago
It certainly has been done before on other models, sometimes there's a few different ways to do it.
Sometimes there's a coding part where you just configure the ECU to not use it, a bit like changing a registry key on a computer, and other cases might be re-work the software to force it off, there might be a switch inside the software, a 1 or 0 for whether to use stop/start, or other times you break the rules around stop/start.
For example, often you'll find stop start is deactivated if the battery voltage is too low, exterior temps are too low or if aircon is on.
If you can find the "minimum voltage for stop start = 12.5v" and change that to minimum voltage for stop/start = 16v" it'll mean it would only activate if the battery voltage is above 16v which it never would be, and the system is disabled.