?OBDDFM AFM/DFM DISABLER? ? Pug and Play-Just plug into your onboard OBD-II port and it immediately start to work. ? Compatible with V6 and V8 General Motors (GM) vehicles equipped with active or dynamic fuel management, including cars, trucks, and SUVs. ? Will not reprogram your factory ECU, Unplug it to back to factory settings. ?IMPORTANT INFORMATION? ? Please check compatibility before purchasing. ? This OBDDFM AFM DFM device is NOT currently compatible with the 10-speed transmissions models and 2022+ Refresh models. ? When the device was plugged into the port, blue lights will flash in sequence and then turn off. It just indicated that the device was connected and working normally. ? If the OBDDFM device is not used for a few days, please take the product off to avoid running out of battery. ? To verify that the vehicle remains in V8/V6 mode, check the dashboard display or feel the strong, smooth power output. ? If the lights don't work as expected, make sure the OBD-II port is securely connected and confirm vehicle compatibility. ? The two center lights are for engineering diagnostics only and are not related to normal operation. These lights can be safely ignored. ?Indicator Lights Guide? ? When Connected Blue indicator lights will illuminate when the device is connected to the vehicle. ? Engine Running ? One solid blue light remains on ? One flashing blue light blinks every few seconds ? Engine Off The flashing blue light will remain on for about 3 minutes before the device enters standby mode.