CarNerve: OBD2 & engine faults

Plug in a cheap OBD-II adapter and find out what is really going on with your car - no subscription, no account.

WHAT MAKES CARNERVE DIFFERENT

★ KNOWN FAULTS OF YOUR ENGINE
383 curated entries on recurring factory faults - keyed by ENGINE FAMILY, not by the marketing model name. Symptoms, how to spot them, related fault codes and sources. This answers the question you actually have: not "what does P0299 mean", but "what tends to break on my 2.0 HDi, and how will I know".

★ WE DO NOT GUESS
Every entry carries a source and a confidence level. When something cannot be read from the OBD socket, we say so instead of inventing an answer. We also do not quote repair prices - a figure from one market at one moment misleads; we say whether it is expensive.

★ CHECK A CAR BEFORE YOU BUY IT
Buying used? CarNerve checks whether someone cleared the warning light shortly before you burned up. It combines readiness monitors, distance since codes were cleared, permanent and pending codes, and distance driven with the light on - and says plainly what follows. Plus questions for the seller derived from the known faults of that exact engine, and a PDF report you can send to a mechanic or use when negotiating.

★ NO CODE? START FROM THE SYMPTOM
Tick what you observe - hesitation, smoke, noise, power loss, hard starting - and we show the known faults of that engine which produce those symptoms. Works without an adapter.

★ CODE DESCRIPTIONS MATCHED TO YOUR CAR
The same P1xxx means different things across manufacturers and fuels. CarNerve picks the description by make and fuel type from your car profile — 466 codes, with causes, confidence levels and native ECU codes (BMW, Mercedes, Volvo).

★ FUEL TRIMS - SEE THE PROBLEM BEFORE THE LIGHT COMES ON
For petrol engines we read fuel trims and oxygen sensors, and explain what they mean. The same number means one thing at idle (vacuum leak) and another under load (fuel delivery) - you get a ranked list of where to start looking.

★ A HISTORY THAT ACTUALLY TELLS YOU SOMETHING
The second and third check of the same car say more than the first. You see which code keeps coming back and what is new since last time - and we separately flag a code that returned AFTER being cleared, because that is the strongest proof the fault is real.

★ REMINDERS THAT SPEAK UP ON THEIR OWN
Insurance, roadworthiness test, oil change, timing belt. Local notifications 30, 7 and 1 day before, and on the day. No cloud, no account - everything stays on your phone.

WHAT IT DOES

• Read and clear engine fault codes (modes 03, 07, 04)
• Permanent and pending codes, freeze frame data
• I/M readiness - the same thing the test station reads
• Live data: rpm, temperatures, boost, common-rail pressure, voltage
• Petrol: fuel trims and oxygen sensors, with an assessment of what they mean
• DPF parameters (mode 22) for supported diesels - soot mass, ash, regeneration
• VIN reading and automatic vehicle identification
• Step-by-step troubleshooting for the 28 most common codes
• A test-drive plan tied to the known faults of that engine
• Multi-car garage, check history, reminders, PDF report
• Fully bilingual: English and Polish - the interface AND the whole knowledge base

WHAT WE DO NOT PROMISE

The OBD-II standard covers only the engine controller and the emissions system. CarNerve does NOT read ABS, airbags, automatic transmission or body electronics - those modules use manufacturer-specific protocols and only a brand tool can see them. We say this on the results screen, not in the small print.

WHAT YOU NEED

A Bluetooth OBD-II adapter (ELM327). On iPhone it must be a Bluetooth LE adapter; on Android Bluetooth Classic works too (pair it in your phone settings first). Every car from 2001 (petrol) and 2004 (diesel) has an OBD-II socket.