The BMW B48 engine is everywhere in independent bays. Introduced in 2014 as the 2.0-litre turbocharged four-cylinder of BMW's modular B-series family, it powers everything from the 1 Series hatch to the X3 crossover, plus a long run of MINI models and the 2.0-litre Toyota Supra. For a locksmith, that ubiquity has a catch: when the DME is locked, retrieving the ISN needed for key programming has meant pulling the engine control unit and reaching for specialist bench tooling — or shipping the job out. Xhorse has just changed that equation. A new software update for the VVDI Key Tool Plus adds "BMW B48 LOCK (Read)," letting the tool extract the ISN from a locked B48 DME in bench mode.
The feature shipped at the end of September 2026 and is aimed squarely at the all-keys-lost and DME-swap jobs that used to eat an afternoon. Here is what it does, what it does not do yet, and how it fits into a working BMW key-programming workflow.
What the ISN Is — and Why It Matters
The ISN, or Individual Serial Number, is the security code the DME exchanges with the vehicle's CAS, FEM, or BDC module to authorize an engine start. It is the linchpin of the immobilizer handshake. Every BMW key job that touches the engine control unit depends on it: all-keys-lost, adding a spare key, replacing a failed DME, or re-aligning a replacement ECU to the vehicle. Without the ISN, none of those procedures can complete.
The problem is that on many B48 vehicles the DME is locked. A standard OBD read will not hand over the ISN, which is precisely what pushed shops toward bench work with a specialist programmer, or toward sending the unit out for a few days. That delay and cost is the friction point Xhorse is targeting with this release.
What "BMW B48 LOCK (Read)" Actually Does
The new function arrives through the Key Tool Plus's update channel. It reads the ISN from a locked B48 DME in bench mode, using the Bosch ECU Adapter to establish the connection. Xhorse's own reference example is a 2022 BMW X1 with the B48 engine, processed on the bench to pull the DME ISN. That matters because it tells you the expected workflow: the DME comes out of the car, goes onto the bench, and the read happens there rather than through the OBD port.
One limitation to flag up front: the function is read-only. It extracts the ISN, but it does not write, modify, or clone the DME data. For a technician, that is the important expectation to set — what you get from this release is the ISN value you need to feed into the key-learning step, not a full DME programming solution.
Why Locksmiths Should Care
There are three practical reasons this update matters more than the headline suggests.
First, volume. The B48 family is one of the most common modern petrol units in the European and Asian fleets that independent shops see daily, so a locked-DME ISN read is a recurring job, not an occasional one. Second, margin. All-keys-lost and DME-swap work is high-value, but it has historically been gated by ISN access; shops without bench tooling either turned the job away or ate the cost of outsourcing. Third, cost. Running the read on a key programmer you already own beats paying for a bench subscription or a multi-day courier to a specialist lab.
For a shop already invested in the Xhorse ecosystem, the update is effectively free capability — it ships through the software channel, so the Key Tool Plus simply does more without a new hardware purchase. That is the same logic that makes a broad ECU tooling setup pay for itself: coverage that expands by software update extends the life of the hardware already on the bench.
How It Fits the Workflow — and Where to Be Careful
The typical sequence is straightforward. Confirm the vehicle and engine, remove the DME to the bench, connect it through the Bosch ECU Adapter, run the B48 LOCK (Read) function, and capture the ISN. From there the key-learning step proceeds on the vehicle as normal, with the ISN in hand and the correct smart key remote or key chip for the platform.
Two precautions apply. First, verify ownership before starting any key or ISN work — the ISN is the gate to the immobilizer, and retrieving it should only ever be done on a vehicle the customer is documented to own or has authorization to service. Second, keep the Key Tool Plus update channel current. Coverage like this ships as a database update, and a tool that is months behind may not list the B48 LOCK entry when the job is sitting on the bench.
What to Expect Next
Read support is almost always the first step in this kind of rollout. A read-only ISN extraction tends to be followed, in later updates, by write and alignment functions once Xhorse has validated the read across more B48 variants. For now, the message is simple: the locked B48 DME is no longer the dead end it was, and the shops that already keep a Key Tool Plus on the bench get the capability for nothing more than staying current on updates.
For locksmiths building out their BMW work, this is the kind of quiet release that changes the job quote the next time a B48 rolls in with no keys. The engine is already in your bay; the question is whether your tooling can read its most important number.
Note: ISN retrieval and key programming should only be performed on vehicles you own or have documented authorization to service. Always verify ownership before starting any immobilizer or security-related procedure.
