What a scanner cannot do
What a scanner cannot do: 10 pieces on carscan.app — what it means, what to look at in the live data and where to start. Open and free, no app needed.
Starter turns, car will not start: P0513, key not recognised
The starter spins briskly, there is fuel, there should be a spark — and the engine will not catch. If a key or car-with-padlock symbol flashed on the
6 September 20264 min
Control unit faults on itself: P0600, P0601, P0603, P0606
A code about an internal control unit fault sounds like a bill for thousands. In reality the culprit is usually not the unit but its power supply — an
6 September 20264 min
«Lost communication»: codes U0100, U0101, U0121, U0140
Everything lit up at once — check, ABS, stability — and the scanner returned codes starting with U. This is almost never fried electronics: usually a
6 September 20264 min
Transmission codes: P0700, P0715, P0720, P0741, P0750
The automatic started jerking, hesitating before shifts or «slipping» on the motorway — and the scanner shows P0700. Here is what stands behind it and
6 September 20265 min
Hybrids and EVs: what an ordinary scanner will show
The same socket, but less data than people expect. Honestly: what reads, what does not, and why the battery's health is not checked this way.
5 September 20263 min
Why a scanner does not show ABS, airbag and gearbox faults
The ABS light is on, and the app says «no faults». The tool is not broken — it is looking elsewhere, and here is why.
5 September 20267 min
What the letters and digits in a fault code mean
P0171, C0035, U0100 — five characters, and each says something. Once you can read them, an unfamiliar code makes sense without a reference.
5 September 20264 min
How this differs from a dealer scanner
The honest answer: by a lot. Here is what any car gives, what depends on the make, and when only a dealer tool will do.
5 September 20263 min
«No answer» is not «no faults»
The difference between silence and a clean memory is expensive. Most cheap scanners do not tell the two apart.
2 September 20262 min
Why the service reset does not work on every car
It is easy to promise a reset on every car. We say plainly where it will work and where it will not — and why.
2 September 20262 min