A client came to us with a 2023 KIA Sportage equipped with a two-litre diesel engine. The system periodically showed fault code P204B:00 — “Reductant Pressure Sensor Circuit: Range/Performance”.
During diagnostics, it was determined that the urea tank assembly needed to be replaced.
The vehicle was brought to us with a specific question: is it possible to delete this system?
In this article we will walk through every step of solving the problem and describe the difficulties we encountered along the way.
Engine Control Unit MD1CS012:
– The engine control unit is located to the left of the battery.
SCR Control Unit – VD1CP030:
– The SCR control unit is located under the driver’s seat. To remove it, simply undo the 4 seat mounting bolts and slide the seat backwards. It is not necessary to remove the seat from the vehicle.
As expected — reading this ECU (MD1CS012) is not available, though we decided to check in case something had changed (as of 26.02.2026 reading is still not possible). We connected via module 92.
The SCR unit VD1CP030 — also cannot be read….
Replacing the SCR control unit is currently the only solution for this vehicle. The fact is that Korean vehicles previously used DCU17PC42/43 units in which read/write is unlocked and we can dig into those units’ settings.
To start with, we tried installing a DCU17PC42 we had on hand from a 2019 Hyundai Palisade with the following software version:
We flashed the unit with firmware that had been tested on several vehicles and installed it in the car. The fault codes cleared and we all applauded. We sent the client out for testing. The next day the client reported that when the ignition was switched on, “exhaust system malfunction” appeared on the screen for 0.5 seconds. A day later a counter was added to this, anxiously counting down the kilometres to vehicle lockout. The most interesting thing was that it would light up and go out so quickly that you could only read it on video replay. Several more attempts to “recalibrate” something or “tweak” something else changed nothing. It became clear that the experiments with the DCU17PC42 unit had led nowhere — the problem remained. We began looking for a DCU17PC43 unit. One turned up by chance — from a 2021 Mohave whose engine ECU can be read (EDC17CP62) and whose SCR unit can be physically removed to delete SCR.
Afterwards, firmware without SCR was written to this unit and it was installed in the vehicle — now everything works correctly: the SCR system is disabled, there are no fault codes, and nothing lights up on the dashboard.
But that turned out not to be the end of it! When we replaced the ECU the first time, we disconnected the urea injector connector (just in case). But even that was not enough — the pump inside the tank also had to be physically disconnected!
