Read-only by design, and what the app can and cannot send

Every message to your vehicle passes a built-in safety guard. Anything that isn't a read is refused in the code – there's no hidden setting to turn it on.

What is allowed

• The standard OBD-II reads: live data, freeze frame, stored, pending and permanent codes, the on-board test results and vehicle information such as the VIN.
• A few Ford readings, such as transmission temperature and tire pressures, plus the standard module identification IDs.
• Reading the codes a module holds, at any module in the standard diagnostic address range.
• A fixed list of adapter set-up commands, so the adapter can talk to the vehicle at all.

What is always refused

Programming, module configuration, security unlocks, resets and actuator tests are blocked in the code itself. So are special sessions, memory reads, adapter reprogramming, raw commands and anything the guard does not recognise. Changing which module is addressed is not permission to do anything to it: every one of those stays blocked at every address.

Nothing received from the internet can add to the allowed list. Remote controls from Drive DTC can only turn features off, for example pause clearing codes while a problem is looked at.

The one exception

The one action that changes anything is clearing trouble codes, and you have to type CLEAR to confirm. Every message is shown in the app's safety log. Only engine and transmission codes are cleared. See Clear trouble codes.

See it for yourself

App → Safety shows what Drive DTC is allowed to send to the vehicle, and a live log of everything it did send: the Allowed (reads only) list, the Always blocked list, how many messages were sent and blocked this session, and a traffic log, newest first. The status bar on every screen ends with Read-only guard active.