If you are going to be racing, or dynoing your 2015 and newer mustang we ALWAYS recommend unplugging the dyno plug. But what and where is the dyno plug?
Its a magic plug under the hood of the car that goes to no where. When you unplug it, it will 100% disable TCS and advancetrac until you plug it back in. This is a huge benefit to anyone racing their car.
On 2018+ vehicles if you shut off traction control with the button it can and will come back on and try to do anything possible to stop the spin. In some setups this can actually damage the engine.
So we recommend unplugging this plug anytime you are going to be racing.
The plug is located under the hood of the vehicle to the right of where the stock airbox would be on the fender apron.
The picture attached shows the plug and its location.
The ABS and TCS lights will be on when this is unplugged. Once you plug it in and start driving they will go out again.