Notes from the software-defined vehicle
Engineering notes and executive perspectives on diagnostics, cyber-security and the software that now defines the vehicle — in Diadrom's own words.
The four notes everything else builds on
New to off-board diagnostics? Read these in order.
Off-board vs on-board diagnostics: where the engineering lives
Every vehicle carries diagnostics on board, but the deep work — identifying ECUs, reading faults, coding and reprogramming them — happens off-board, in the tools and data that sit outside the vehicle. Here is how the two sides differ, and why the durable engineering lives on the off-board side.
Read 02 Engineering · ~4 min · ExplainerUDS protocol (ISO 14229) explained: a guide to the services
Unified Diagnostic Services is the language almost every modern ECU speaks to the outside world. This is a working engineer's tour of ISO 14229: the request-response model, the sessions, the services you will actually use, and how it all rides over CAN and IP.
Read 03 Engineering · ~4 min · ExplainerSOVD vs UDS: diagnostics for the software-defined vehicle
Service-Oriented Vehicle Diagnostics (SOVD) is the emerging API for diagnosing software-defined vehicles. Here is how it differs from classic UDS, why it is arriving now, and why the two will run side by side for years to come.
Read 04 Engineering · ~4 min · ExplainerECU flash programming over UDS: how reflashing actually works
Every ECU is reflashed many times in its life — on the production line, in the workshop, increasingly over the air. The UDS services involved fit on one page. What separates a demonstration from a production bootloader is everything that happens when the sequence goes wrong.
ReadSoftware defines premium — the 7 Pillars
Diadrom's white paper on diagnostics across the lifecycle — the framework behind every note on this page. Subscribers to Diadrom Insights receive the full paper.
All notes, by discipline
23 of 23 notes
Abstracting the HSM: portable security for the bootloader
As software-defined vehicles raise the cyber-security bar, the cryptography in a bootloader is increasingly offloaded to a Hardware Security Module. Putting a hardware abstraction layer between the two keeps the code portable, testable and fast to move between silicon vendors.
Read Regulation · ~3 min · PerspectiveThe EU Data Act: the first domino of the software-defined vehicle
From January 2024, EU law obliges connected products to open up the data they generate. For carmakers that is not just a compliance task — it is the regulatory push that makes the software-defined vehicle inevitable, and an opening for whoever can turn vehicle data into services.
Read AI · ~3 min · PerspectiveAutomotive AI is only as good as the data it learns from
Generative AI has largely run out of fresh human-written data to learn from. In the vehicle, the next edge is not a bigger model — it is real, contextual data from the car itself, which the software-defined vehicle and the EU Data Act are finally unlocking.
Read Strategy · ~3 min · PerspectiveTaming the software-defined vehicle with diagnostics
The software-defined vehicle multiplies complexity faster than teams can test it. The way to tame that complexity is not more tools — it is diagnostics as the control plane: one source of truth, one communication framework, one aligned tool chain across the lifecycle.
Read Fundamentals · ~4 min · ExplainerStart hereOff-board vs on-board diagnostics: where the engineering lives
Every vehicle carries diagnostics on board, but the deep work — identifying ECUs, reading faults, coding and reprogramming them — happens off-board, in the tools and data that sit outside the vehicle. Here is how the two sides differ, and why the durable engineering lives on the off-board side.
Read Engineering · ~4 min · ExplainerStart hereUDS protocol (ISO 14229) explained: a guide to the services
Unified Diagnostic Services is the language almost every modern ECU speaks to the outside world. This is a working engineer's tour of ISO 14229: the request-response model, the sessions, the services you will actually use, and how it all rides over CAN and IP.
Read Engineering · ~4 min · ExplainerWhat is ODX? The ISO 22901 diagnostic data layer, and PDX
UDS lets a tester talk to an ECU, but it does not tell the tester what to say. ODX is the formal, vendor-independent description that closes that gap, and PDX is how it ships. Here is what that means in practice.
Read Engineering · ~4 min · ExplainerStart hereSOVD vs UDS: diagnostics for the software-defined vehicle
Service-Oriented Vehicle Diagnostics (SOVD) is the emerging API for diagnosing software-defined vehicles. Here is how it differs from classic UDS, why it is arriving now, and why the two will run side by side for years to come.
Read Security · ~4 min · Standards briefSecuring the diagnostic channel: ISO 21434, UN R155 and UDS 0x29
Type approval now turns on cyber-security, and the diagnostic channel is one of the most exposed surfaces a vehicle carries. This is what the regulations demand, and why the industry is moving from seed-key SecurityAccess to certificate-based authentication.
Read Engineering · ~3 min · ExplainerECU baseline, variant coding and configuration management
A modern vehicle platform carries thousands of software and configuration variants, each of which must be exactly right in every ECU that leaves the line. Holding one authoritative record of what belongs where is the difference between a controlled programme and a slow drift into the unknown.
Read Engineering · ~4 min · ExplainerDoIP and ISO 13400: diagnostics over IP explained
Diagnostics is moving off the CAN bus and onto automotive Ethernet. DoIP, standardised as ISO 13400, is how that happens — and the good news for engineers is that your UDS services come along for the ride, unchanged.
Read Defence · ~4 min · PerspectiveThrough-life defence diagnostics for long-life systems
A fighter, a missile system or a fleet vehicle is expected to serve for thirty years or more. The commercial silicon, operating systems and test benches it depends on are not. Keeping a platform diagnosable across that gap is a readiness and sovereignty question, not a maintenance footnote.
Read Engineering · ~4 min · ExplainerAutomating UDS diagnostic verification in CI and on HIL
In a software-defined vehicle the code changes constantly, and any change can silently break a diagnostic. The only durable defence is to re-verify diagnostic behaviour automatically, on every build.
Read AI · ~3 min · PerspectiveControlled AI for mission-critical diagnostics
Every technical organisation is being told to adopt AI. In vehicles, defence platforms and industrial systems the question isn't whether AI creates value — it's whether an AI recommendation can be trusted when it matters. That trust has to be built on a provable foundation.
Read Engineering · ~4 min · ExplainerStart hereECU flash programming over UDS: how reflashing actually works
Every ECU is reflashed many times in its life — on the production line, in the workshop, increasingly over the air. The UDS services involved fit on one page. What separates a demonstration from a production bootloader is everything that happens when the sequence goes wrong.
Read Engineering · ~6 min · Standards briefISO 24089: software update engineering, explained
Software updates got their own engineering standard in February 2023. ISO 24089 does not tell you which update platform to buy — it defines what an organisation must be able to do before it changes the software in a vehicle. Here is what the standard covers, and how it relates to UN R156.
Read Security · ~7 min · Standards briefUN R155 CSMS requirements and the diagnostic channel
A certified Cyber Security Management System is now a condition of vehicle type approval, and the diagnostic channel is one of the few attack surfaces the regulation names outright. Here is what UN R155 actually requires, where diagnostics appears in its threat catalogue, and what the assessment examines.
Read Defence · ~7 min · Standards briefISO 26262 vs MIL-STD-882E: same discipline, two worlds
Automotive engineers classify hazardous events into ASILs; defence programmes assign risk codes and route them to an acceptance authority. Both are answering the same question — how safe is safe enough, and how do you prove it? Here is where the two worlds genuinely differ, and what carries across.
Read Defence · ~7 min · Standards briefWhat H SystSäk 2022 asks of suppliers
H SystSäk 2022 shapes system safety in Swedish defence procurement. For a supplier it arrives as contract requirements: a plan, a chain of analyses, a living risk log and a formal statement before delivery. Here is the work in delivery order — and where automotive discipline carries.
Read Engineering · ~4 min · Buyer's guideOff-board diagnostics and ECU flashing: choosing a toolchain, not just a tool
Flashing an ECU on a bench is the easy part — a laptop, a vehicle interface, a piece of flashing software, and the sequence runs. What decides a programme is what carries diagnostics and reprogramming into serial production: the OEM security model, decades of obsolescence, takt time, thousands of variants and a traceable record. This is a buyer's framework for telling a tool apart from a toolchain.
Read Strategy · ~7 min · Buyer's guidePå svenskaAtt välja leverantör av diagnostikmjukvara för fordonsindustrin: frågorna som avgör före avtalet
Licenspriset är den minsta posten. När en fordonsplattform ska hållas diagnostiserbar i decennier avgörs leverantörsvalet av annat: livscykelkostnad, inlåsning, standardtäckning och närheten till dem som bär arbetet. Här är frågorna en svensk inköpsorganisation faktiskt arbetar sig igenom — fram till det som bör stå i er RFI.
Read Security · ~4 min · Standards briefUN R156 compliance: what the SUMS actually requires
Since July 2024, a new vehicle without a certified Software Update Management System cannot be registered, sold or enter into service in the EU. Here is what UN R156 concretely requires, why the update record is harder than the update mechanism, and where ISO 24089 fits.
Read Defence · ~4 min · PerspectivePå svenskaFörsvarsdiagnostik genom livscykeln: beredskap är att kunna ställa diagnos
Ett luftvärnssystem, ett stridsfordon eller en fordonsflotta förväntas tjänstgöra i trettio år eller mer. Den kommersiella elektroniken, operativsystemen och testverktygen den beror av gör det inte. Att hålla en plattform diagnostiserbar över det gapet är en beredskaps- och suveränitetsfråga — inte en underhållsfotnot.
ReadThree routes through, by what you're here to do
Each path is a curated sequence of the notes above — read in order, they build a complete picture.
I'm an automotive diagnostics engineer
- 1Off-board vs on-board diagnostics: where the engineering lives
- 2UDS protocol (ISO 14229) explained: a guide to the services
- 3What is ODX? The ISO 22901 diagnostic data layer, and PDX
- 4DoIP and ISO 13400: diagnostics over IP explained
- 5ECU flash programming over UDS: how reflashing actually works
- 6SOVD vs UDS: diagnostics for the software-defined vehicle
I run a defence programme
- 1Through-life defence diagnostics for long-life systems
- 2ISO 26262 vs MIL-STD-882E: same discipline, two worlds
- 3What H SystSäk 2022 asks of suppliers
- 4Controlled AI for mission-critical diagnostics
Också på svenska: Försvarsdiagnostik genom livscykeln
I'm evaluating diagnostic tooling
- 1Off-board diagnostics and ECU flashing: choosing a toolchain, not just a tool
- 2Taming the software-defined vehicle with diagnostics
- 3ECU baseline, variant coding and configuration management
- 4Automating UDS diagnostic verification in CI and on HIL
Then: the 7 Pillars white paper · Svensk inköpsorganisation? Att välja leverantör av diagnostikmjukvara
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