A large share of the UK Hyundai parc is now old enough that the engine ECU, rather than the engine, is what leaves a car stranded. The common-rail diesels that sold in volume through the i30, ix35, Santa Fe and Tucson years were built to keep running long after the finance was cleared, and many still are – bodyshell sound, engine willing, but the control unit governing fuelling and injection timing has developed an electronic fault the car can no longer drive around. That is the specific problem we deal with: not the mechanics of the engine, but the failure on the board inside the unit that manages it.
Hyundai’s engine management splits cleanly down the fuel line. The concrete, documented backbone here is diesel – the CRDi common-rail range running Bosch EDC control units, which is where our Hyundai part-number library sits and where our engineers see the most repeatable failures. The petrol side, built around Korean-made engine ECUs across the smaller cars, we treat differently and more cautiously, for reasons set out below. Establishing which of those two worlds a unit belongs to is the first thing we settle, because the fault behaviour is not the same.
We repair Hyundai engine ECUs at component level – identifying and correcting the exact fault on the circuit board rather than swapping the unit for another. On the diesel side we document two Bosch EDC references in full, an earlier and a later generation of the same common-rail control family. The first is the Hyundai CRDi Bosch EDC15C7 diesel engine ECU, the earlier-generation unit fitted across the older common-rail diesels. The second is the later Bosch EDC16C39 CRDi unit, which took over as the range moved on. Both are mainstream failures we know in detail and hold exchange units for where documented.
The petrol side we handle honestly rather than by catalogue. Hyundai’s petrol engine control was built by its Korean supplier across the i10, i20, i30 and related range, and we do not publish a held part-number page for those units. Because they are engine ECUs of exactly the type we work on, our technical team confirms coverage on the specific petrol unit you have – by part number and by the fault it is showing – instead of guessing from a list. Send us the unit with the vehicle details and the symptom, and we tell you plainly whether it is a repair we can carry out before any chargeable work begins. We would rather stand behind an assessment of your actual unit than list numbers we cannot support.
An engine ECU fault on a Hyundai is electronic, not mechanical, and it tends to arrive through a familiar set of causes – heat, vibration, moisture and a rough supply voltage doing their work on the board over time. On the Bosch EDC diesel units the recurring failures cluster around the internal drivers, regulators and relay stages; on the petrol units the physical causes are much the same even where the layout differs.
A limp-mode warning or a dead no-start does not, on its own, prove the engine ECU has failed. A collapsed sensor supply, a chafed harness, a corroded earth or a tired battery can throw the same lights and the same symptoms, and fitting a healthy ECU cures none of them. So we never take the unit’s guilt for granted. Every ECU that reaches the workshop is logged, visually inspected and electrically tested first, then taken through fault-specific diagnostics under a microscope with temperature-controlled rework equipment. Only a fault genuinely inside the unit is repaired; if the evidence points to the wiring or the vehicle, we tell you that instead.
This is also why repairing the original unit is the cleaner route on a Hyundai than replacing it. A component-level repair returns your own ECU, so it keeps the coding and security relationship it already holds with the car and refits plug-and-play – no dealer reprogramming, no key or immobiliser pairing to arrange afterwards. A replacement unit brings exactly that reprogramming work with it; a repair sidesteps the lot.
We run as a mail-in service covering the whole of the UK, so wherever the car sits, the unit comes to our workshop. Remove the engine ECU, or have your garage remove it, and send it in with the vehicle details and a note of the fault. We test and diagnose it, come back to you with the outcome and an estimate, and no chargeable work starts until you authorise it. Every repair is carried out in-house by our own engineers, tested before and after, and covered by a 24-month warranty on the specific repair, using OEM-grade parts that meet or exceed the original specification.
To begin, complete the Repair Form on our contact page for a diagnosis and quote for repair. If your fault is on another make, our What We Repair overview shows the full range of engine ECUs we cover.
Type: Bosch Engine Management Fits: Hyundai Fuel: Diesel Ref: ECUT69300 Note: This ECU may also fit other models. In the second column of our table, 39101-27825 and 39113-27825 end in the same five characters, so any number read
Type: Bosch Engine Management Fits: Hyundai Fuel: Diesel Ref: ECUT68250 Note: This ECU may also fit other models. Our table for this page runs in number order. Its Bosch numbers climb from top row to bottom, so the