Kia's move to the 4A chip on its newer smart keys has quietly made key programming harder. On the 2019–2022 Kia Soul, the old tricks that worked on earlier 46-chip and 8A transponder systems no longer apply. The first — and usually the hardest — hurdle is reading the PIN code. Get that step wrong and the whole job stalls before a single key is cut. The good news is that the Xhorse VVDI Key Tool Plus gives technicians a reliable, repeatable path through this exact step.
Why the 4A chip changes key programming on Kia
For years, Kia and Hyundai vehicles relied on conventional transponder chips — the 46, the 8A, and similar legacy families — that a locksmith could read with a fairly standard EEPROM or OBD routine. The 4A chip, which Kia rolled out across its smart-key lineup, is a different animal. It wraps the immobilizer data in stronger encryption and ties the PIN retrieval to a secure, server-backed calculation rather than a local read.
In practice, that means the PIN code is no longer sitting in a chip you can simply dump. Many programmers that handle older Kia systems without issue will fail, time out, or return garbage on a 4A-equipped Soul. The result is a growing pile of jobs where a locksmith arrives with the right blank key but cannot get past the PIN gate. That is exactly the gap the Key Tool Plus closes.
What you need before you start
The process is short, but it is not forgiving of sloppy preparation. Before you connect anything, make sure you have three things in place:
- A charged Xhorse VVDI Key Tool Plus. The workflow runs entirely through the tablet, from menu navigation to the final server handshake.
- A stable Wi-Fi or mobile-hotspot connection. The 4A PIN is calculated on Xhorse's server, not on the device. A connection that drops mid-read means starting over.
- The vehicle's key status clear in your head. The exact ignition or hazard-light sequence depends on whether you have a working key or are dealing with an all-keys-lost situation.
Do not skip the connection check. The number one reason a 4A PIN read fails in the field is a hotspot that flaked out halfway through the upload — not a problem with the tool.
Reading the PIN code, step by step
The full menu path on the Key Tool Plus is straightforward: IMMO Programming → Kia → Read PIN Code → Password Reading (4A Chip) → Read PIN Code. From there, the key status determines your next move.
Step 1: Set the vehicle into the right state
If you still have a working key, turn the ignition on and leave it there. If the job is all-keys-lost, do not hunt for an ignition position — switch on the hazard lights instead. This tells the vehicle to wake the immobilizer circuit and lets the tool complete its secure-access handshake. Getting this wrong is the second most common cause of a failed read.
Step 2: Establish secure access and upload
Once the vehicle is in the correct state, the Key Tool Plus establishes secure access to the 4A system and uploads the necessary data to the server. This is the point where your connection matters most. Let the device finish the upload before you touch anything else.
Step 3: Wait for the server calculation
Password retrieval is not instant. The tool is sending data out and waiting for the calculated PIN to come back, and this can take a little time. Resist the urge to interrupt, disconnect, or retry. When the tool prompts you, switch the ignition off — the password will be retrieved successfully at that point.
Step 4: Save the PIN
When the PIN appears, take a photo of it immediately. This is the single most useful habit a key programmer can build. A lost PIN at the end of a long job is a self-inflicted wound, and the photo also gives you a reference for any follow-up work on the same vehicle.
Why the Key Tool Plus handles newer Kia systems
The reason the Key Tool Plus succeeds where generic programmers stumble is the server-backed calculation. Instead of trying to reverse-engineer the 4A encryption on-device, the tool offloads the heavy lifting to Xhorse's infrastructure, which is continuously updated as Kia and Hyundai roll out new variants. That architecture is why a device can stay current on a fast-moving chip family without waiting for a bulky local firmware refresh.
For a shop that already does volume key work, that matters. The same tablet that reads a 4A PIN on a Kia Soul also covers the broader Hyundai and Kia lineup, plus the key cutting, remote, and chip functions that surround a full key-replacement job. It is one device pulling several jobs together, which is exactly what a busy auto locksmith or workshop wants.
Common mistakes to avoid
Most failed 4A reads come down to three avoidable errors. First, an unstable connection that drops during the upload. Second, turning the ignition off before the tool tells you to, which aborts the retrieval. Third, forgetting to record the PIN the moment it appears. None of these are tool failures — they are process failures, and they are easy to prevent once you know to watch for them.
It is also worth remembering that "all-keys-lost" and "adding a spare" are not the same workflow on these systems. The hazard-light path exists specifically for the lost-key scenario, and using the wrong sequence will simply fail.
After the PIN: programming the smart key
Once the PIN is in hand, the rest of the job is familiar territory. The PIN unlocks the immobilizer step so you can program a new smart key, pair the remote, and complete the relearn. From there, the work flows into the equipment most shops already lean on — key programmers for the immobilizer side, remote keys for the fob, and the right key chips to match the vehicle's transponder family.
Reading the 4A PIN on a 2019–2022 Kia Soul is no longer a gamble. With the Xhorse VVDI Key Tool Plus and a little discipline around connection and sequence, it becomes a repeatable ten-minute step — and the kind of job that keeps a modern locksmith shop competitive as Kia and Hyundai continue to harden their systems.
