Methodology: How We Build Code Pages

Every page on Fix Error Code is generated from a structured record in our code database. This page explains what those records contain, how the ratings are meant to be read and what checks a page has to pass before it appears in search engines.

Code identity and definition

For OBD-II codes, the code identifier and its standard definition come from SAE J2012 and ISO 15031-6, the standards that define generic diagnostic trouble codes. Manufacturer-specific codes and appliance error codes come from manufacturers' public documentation. We cross-check definitions against more than one source wherever possible. If a definition rests on a single manufacturer source, the page is marked unverified so you know to treat it with extra care.

Ratings

Severity (1–5)

Severity describes how urgent the fault is. 1 means a minor or cosmetic issue; 5 means stop using the vehicle or appliance now. Codes rated 4 or 5 put the safety advice at the top of the page.

Drivability (vehicles)

Each vehicle code is marked yes, caution or no for whether continued driving is reasonable. "Caution" usually means short, gentle trips to a repair shop are acceptable, but not long drives or heavy loads.

DIY difficulty (1–5)

1 means anyone can do it with no tools; 5 means workshop or technician only. Some systems are always rated professional-only regardless of how simple a job looks – see the safety section below.

Likely causes

Causes are ranked from most to least likely. The percentages are editorial estimates, not measured statistics. They combine the logic of how the code is set, how common each failure is in practice and how often simple causes are overlooked. Use them to decide what to check first, not as a probability you can calculate with.

Diagnostic steps

Steps are ordered so that quick, safe and inexpensive checks come first: reading the full code list and freeze-frame data, visual inspection, connectors and hoses, then measurements and component tests. Each step lists the tools it needs.

Repair costs

Cost figures are rough regional estimates covering parts and labor, shown as ranges. US pages use US dollars; German and Dutch pages use euros. Labor context comes from public statistics (BLS in the US, Destatis in Germany, CBS in the Netherlands). The ranges are orientation only – they are never quotes, and actual prices vary with the vehicle or model, the region and the shop.

Inspection impact

Vehicle pages state whether a code is likely to cause a failed emissions test or smog check in the US, the HU/AU in Germany or the APK in the Netherlands. Where the outcome depends on the circumstances, the page says so.

Field data

Where public data exists, pages draw on open data such as NHTSA complaints and recalls, KBA vehicle data, RDW Open Data, product registries and safety recall databases. The data sources page lists each source and how it is used.

Quality gate

An automatic quality check scores every page before it can be indexed. A page needs at least eight page-specific data fields filled in, and it must differ sufficiently from other pages of the same type: its text similarity (measured by overlapping word sequences) has to stay below 60%. Pages that fail are kept out of search indexes (noindex) until they are improved. Brand-specific variants of a code only get their own page when there is real, distinct data for that brand.

Safety

Gas appliances, mains electricity, microwave internals, refrigerant circuits, airbags, brakes and hybrid or EV high-voltage systems are always marked professional-only. Gas appliance pages contain no DIY repair instructions at all – only the safe user checks the owner's manual allows. More in our editorial policy.