The Jumper Hack
With this hack, a short wire or paperclip is placed between the signal wire and the ground wire. This makes the truck see the auto start-stop button as constantly pushed. When the body control module powers up, it’ll detect the pressed button and toggle the auto start-stop state.
The primary problem with this approach occurs when the signal wire from the body control module briefly flickers. This interruption causes the body control module to detect a subsequent button press and toggle the state. Keep in mind that the button is no longer functional because it has been shorted by the jumper. When it toggles auto start-stop to the 'on' state, it’s stuck 'on'. The only way to turn it back off is to shut the vehicle off and wait for the body control module to power down completely.
This may seem unlikely, but it happens all the time. In fact, within a few minutes of testing the jumper hack at TRL Automotive, this what happened. It can be triggered by something as simple as using keyless entry to unlock the truck. When you use keyless entry, the body control module powers up and the auto start-stop state toggles. Then when the truck is started, it’s a gamble whether or not the signal wire will flicker and land in the wrong state.
Not only does this hack not preserve the functionality of the auto start-stop button, but it also comes with the aggravation of occasionally getting stuck in the 'on' state.