The flagship · the mechanic
Shiro's first job, and the furthest along: reading what your car reports about itself, telling you what it means and what to do, and quietly watching for drift.
The check-engine light hasn't changed in 40 years.
One bulb for thousands of possible failures.
Sources: Hedges & Co. (vehicles on U.S. roads) · AAA (repair cost, affordability)
Reactive
It says nothing while a problem is still small.
Generic
The same vague code for every car on the road. Nothing about yours.
Silent
A glowing symbol and a number. No what. No why. No idea what it will cost you.
Shiro is three mechanics in one.
The same diagnosis, spoken to the person in the seat — driver, do-it-yourselfer, or professional.
Driver
Plain language, proactive. No codes, no jargon — just what you need to know, before it becomes a problem.
DIY
What you can check yourself, starting with the reading behind the warning. The sample shows a fuller walkthrough, on a simulated fault.
- Engine cool, key out, before you touch anything.
- Swap the suspect cylinder's ignition coil with its neighbour's.
- Drive, then check: did the misfire move with the coil?
- If it moved: the coil is the part. If not: a pro should check the valvetrain.
Mechanic
Raw telemetry, trend graphs, freeze-frame at the moment of the anomaly, and Shiro's full technical reasoning.
| MISFIRE COUNT | 142 ▲▲ |
| SHORT FUEL TRIM | +9.4% ▲ |
| COOLANT TEMP | 91 °C — |
| ENGINE RPM | 1,880 ~ |
| VS LEARNED BASELINE | +5.8σ |
Not a code reader — a mechanic built to learn your car.
Built to warn before the light
Watches for the small drifts that tend to come ahead of a warning light. On scripted faults in simulation she flagged every one before the simulated light. On our real test car — healthy so far — she has raised zero false alarms, and her warnings stay in a review log until she's proven on a real fault.
Your engine's own normal
Built to learn the actual habits of the actual engine in your driveway — not a factory average for your model year. Swap a part or fix something and she's built to re-learn it, instead of flagging the repair as a fault.
Offline-first
Your driving history lives on hardware you own, not on our servers, and no company server can go dark and take her with it. Cloud help is optional, metered, and can be switched off.
Read-only on your car
She reads, reasons and recommends — she can't change a setting on your car. You stay the driver, and the fix is always yours.
Why the light is late, and what she watches.
The warning light is a pass-or-fail test, shaped mostly by emissions rules. For many faults it also waits to be sure. The car's computer first stores a pending code. The light comes on only if the fault returns on a later drive.
What she watches
She reads the numbers your car already reports — on our real test car, the engine, emissions and electrical systems. She compares them with how that same car runs when healthy. A stray blip doesn't set her off. When a change looks real (a drift from that healthy normal), she flags it and names its system.
Why that can be earlier
Many parts wear gradually, so a fault often starts small. A limit that must fit every car built the same way lets a small change pass. Measured against how the car itself runs when healthy, that change can stand out. She doesn't wait for a trouble code.
Where it falls short
So far it's shown only on simulated faults, like the boss fight below. A part that fails all at once leaves nothing to spot, and every fault we simulated was gradual. She also needs to see a car healthy before she can tell it's changing.
More detail
Not every fault waits: a few serious ones make the light flash right away. A drift is a reason to get the car checked, not a diagnosis, and the warning light still counts.
Our fault tests are scripted in software. Each is run hundreds of times with random noise, alongside hundreds of simulated healthy drives with no fault. She never sees the light or trouble code the script sets, and none of the healthy drives set her off. A simulated fault runs far faster than a real one, so it says nothing yet about timing on the road.
Sources: California Air Resources Board and U.S. EPA (warning-light rules) · NASA (reliability engineering)
Built to catch an engine problem before the light — shown on a simulated fault.
Our real test car is a common American sedan with well-documented failure modes. Since Aug 2026 we've recorded 48 real sessions off its diagnostic port — 60,376 readings, zero trouble codes. It has stayed healthy, so the fight below is a simulated fault for that kind of engine, not a fault found on the road.
How a heads-up works.
Something's off
One of the engine's vital signs starts drifting away from this car's normal.
System flagged
Shiro names the system that's drifting — here, the engine. This simulated fault is modelled on a known, expensive failure for this kind of engine.
Driver warned
A plain-language heads-up ahead of the light — not a roadside surprise.
Light would set
A conventional system lights up only now.