Note the connector on the end of the device. This is an OBD2 diagnostic connector. If your vehicle is a US model (elsewhere?) and model year 1997 or later, it has one within three feet of the driver’s seat, usually under the dashboard.
On this port are +12 volt power, supplied from the engine control module, and several data lines. Newer vehicles likely use a CAN bus that is essentially grand central — everything uses it for communication.
You should simply not mess with this port if you don’t know what you’re. Here are some good reasons why.
A) Possible ECM damage.
The DC power on this port is limited. Short it out and one of two things happen. If you’re lucky, a fuse in the fuse box blows. Your vehicle shuts down immediately and will not restart until it is changed.
If you are not lucky, a circuit trace or internal pico fuse inside the ECM pops. Same as above, but you CAN’T replace it. Your vehicle is BRICKED. It’s possible the fuse protects only the OBD2 PORT power, in which case no diagnostic tools will work on the port until it’s fixed. Engine fault codes can’t be retrieved or cleared, and it will not pass an emissions inspection.
Internal repair to the ECM will be needed which may or may not be possible.
ECM replacement may be an option on older vehicles, but on newer ones and most European ones, you may find you also have to replace other modules that are keyed to the ECM for security (and service resistance) reasons.
B) “who the fuck is really driving?”
Did you see where I said that *everything* depends on that CAN network on newer vehicles? I mean it.
So here’s what can happen if the device were to mess up the CAN communications.
First off, your vehicle will likely shut down immediately or act really weird for a moment before doing so.
Second, you may lose control and crash. Seriously.
On some vehicles, a lot of functions that really shouldn’t be on the network in my opinion are.
Things like control over power brake assist, power steering, throttle….
I should mention how much I love my car’s hydraulic pedal clutch, old school hydraulic power steering, vacuum brake assist*, and manual transmission about now.
Even more worrisome is the thought that the hotspot device may actually be capable of sending and receiving data on the bus. It has metal pins in all the right places, at least.
Recently it was proven that CAN bus access could be used to remotely cause loss of control on a Chrysler vehicle and run it off into a ditch.
Don’t use this shit. ZTE should be fucking ashamed for even making it. It would have been just as easy to make it plug into a lighter socket; many vehicles have extras, some of which have constant power.
* Actually there is an ABS pump, which may still be able to override brake pedal pressure, but nothing can disable the handbrake for the rear wheels… At least there’s that. WTF is with those electric parking brakes?!