I posted this in the long thread about OBD2 PIDs for the Bolt, but this probably deserves its own thread so that people will notice it.
Some Bluetooth OBD2 dongles have a default Bluetooth pairing password that is the same for all of the same model dongle and cannot be changed. When plugged into the OBD2 port, the dongle is powered up and can also be used to access OBD2 things while the car is "off".
This means that if the dongle is left plugged into the OBD2 port of the parked car, someone else can pair a phone to it and access OBD2 things in your car. With typical apps like Torque Pro and Engine Link, this can mean reading various values and resetting malfunction codes (writing). But since OBD2 allows writing (which is how manufacturer-proprietary functions like reflashing car firmware get done), it is possible that, with a malicious app, someone can do more nefarious things to your car. In theory, a phone paired to the dongle and left attached to the car in a hidden manner could have a malicious app that can detect when the car is being driven and then do things to cause a crash.
So do not leave the dongle attached to the OBD2 port when parked or otherwise not in use. If your dongle can have its Bluetooth pairing password changed, change it to something non obvious.
Note that this is not specific to the Bolt or any other make/model of car.
Some Bluetooth OBD2 dongles have a default Bluetooth pairing password that is the same for all of the same model dongle and cannot be changed. When plugged into the OBD2 port, the dongle is powered up and can also be used to access OBD2 things while the car is "off".
This means that if the dongle is left plugged into the OBD2 port of the parked car, someone else can pair a phone to it and access OBD2 things in your car. With typical apps like Torque Pro and Engine Link, this can mean reading various values and resetting malfunction codes (writing). But since OBD2 allows writing (which is how manufacturer-proprietary functions like reflashing car firmware get done), it is possible that, with a malicious app, someone can do more nefarious things to your car. In theory, a phone paired to the dongle and left attached to the car in a hidden manner could have a malicious app that can detect when the car is being driven and then do things to cause a crash.
So do not leave the dongle attached to the OBD2 port when parked or otherwise not in use. If your dongle can have its Bluetooth pairing password changed, change it to something non obvious.
Note that this is not specific to the Bolt or any other make/model of car.