OBD-II DTC Code Decoder & Repair Cost Lookup 🔧

Turn check-engine trouble codes into ordered repair plans. Feed this Actor a list of OBD-II DTC codes — P0420, P0171, P0300 — and get back what each code means, 3–5 authored procedures in consideration order (up to 8 in reviewed families, where diagnostic steps list no parts), a DIY difficulty rating, aftermarket parts-cost ranges (USD), labor-hour estimates where they exist, step-by-step instructions, and matching part mappings with catalog search URLs.

Powered by MechanicDB: this Actor carries the 9,249 SAE-universal codes — the ones that mean the same thing on every vehicle — with 32,812 ranked repair procedures and 44,588 parts mappings. No scraping, no external calls, instant results.

Manufacturer-specific codes (P1xxx, C1/C2, B1/B2, U1/U2) mean different things on different brands. MechanicDB OEM Complete holds 6,637 of them across 32 makes, all powertrain codes in the P1 and P30–P31 ranges; it has no manufacturer-specific chassis, body or network codes. Pass a manufacturer-range code here and you get a row telling you whether OEM Complete holds that range for the make, with the makes that have codes in it and where to license it when it does.

What this DTC decoder does

• 🚗 Decodes the 9,249 SAE-universal codes in MechanicDB — P0xxx, P2xxx, P34xx and the B0/C0/U0/U3 ranges: the codes that mean the same thing whatever you drive.
• 🎯 Never guesses — a manufacturer-range code means different things on different brands, so instead of inventing an answer this Actor returns an honest found: false that says whether OEM Complete holds that code range for the make, naming the makes that have codes in it when it does.
• 🧰 Authored repair ladder — rank 1 is the first procedure to consider. Execute only when its prerequisites and diagnostic findings support it; rank is not measured cause likelihood, repair success, severity, urgency, or minimum cost.
• 💰 Cost intelligence — parts-cost min/max (USD) and labor hours where estimated (editorial values: parts in US dollars assuming aftermarket parts, labor in hours); unknown costs and labor are null, never guessed.
• 🔩 Parts included — up to 3 part mappings per fix with ready-made catalog search URLs; a mapping can also name a tool, a scan or programming session, or a rental (in reviewed families, diagnostic steps list none).
• ⚡ Offline & deterministic — the dataset ships inside the Actor; a 100-code batch decodes in seconds.

Output — one row per (code, ranked fix)

Field	Description
dtc_code, oem_make, scope	The code, its make (empty for a found SAE-universal code; a not-found row repeats the make you passed, except a manufacturer-range miss, which gives OEM Complete's spelling of a make it lists, e.g. ford → Ford), sae/oem
short_description	What the code means
detailed_technical_explanation	How the ECM detects it and what typically causes it
fault_family, system_category	Diagnosis grouping + Powertrain/Chassis/Body/Network
probability_rank, fix_title	Authored procedure consideration order (1 = first); see the machine-readable ordering context
difficulty_level	Easy DIY / Moderate DIY / Professional Required
est_parts_cost_min_usd, est_parts_cost_max_usd, est_labor_hours	Cost matrix; null when the matching status is unknown
action_type, procedure_rationale	What the step does (inspect, measure, scan, repair, replace, program, verify) and why it is there; null until its family is reviewed
parts_cost_status, labor_status, cost_basis_id	parts_cost_status: estimated, none_required (no parts; costs 0) or unknown (values null); labor_status: estimated or unknown (hours null); cost_basis_id: the editorial cost basis
step_by_step_instructions	•-separated repair steps
parts, parts_names	Part names + catalog search URLs (a row can also name a tool, a scan or programming session, or a rental)
found, reason, oem_tier_makes, upgrade_url	Honest misses: invalid codes and manufacturer-range codes explain themselves
dataset_version, source	Provenance

Export as CSV, JSON, Excel, or via API.

Input

{
  "codes": ["P0420", "P0171", "P0300", "Ford:P1000", "Toyota:P1155"],
  "make": "",
  "onlyTopFix": false,
  "includeParts": true
}

onlyTopFix returns just the first-listed (rank-1) procedure per code; its request behavior is unchanged, and like every item its result carries the five fields above. make (e.g. "Ford", or a per-code "BMW:P1083" prefix) changes the answer only for manufacturer-range codes: their row then names the brand in oem_make. A universal code resolves the same on every make, and a not-found row (an invalid code, or a universal-range code the dataset lacks) only repeats the make you passed in oem_make.

Each run decodes up to 100 codes per run; split longer lists across runs.

Use cases

• OBD-II scanner apps & dongles — code → explanation → ranked fixes without building a database.
• Repair-estimate and shop software — difficulty, parts-cost, and labor-hour matrices per code.
• AI mechanic co-pilots / RAG — structured, provenance-tracked diagnostic context.
• Fleet triage — batch-decode fault lists and sort by cost or difficulty.

FAQ

Where does the data come from? Code-to-definition mappings are compiled from an MIT-licensed SAE J2012-derived public compilation (attribution preserved); explanations, ranked fixes, difficulty tiers, and cost estimates are MechanicDB's original editorial content, built by a deterministic, test-gated pipeline with anti-template and no-fabricated-codes gates.

Does rank mean probability? No. probability_rank is a supported legacy field name for authored procedure consideration order within a code. It is not a measured cause probability or outcome; follow prerequisites and findings before acting.

Are the costs quotes? No — they're editorial values (parts in US dollars assuming aftermarket parts, labor in hours), meant for triage and ballparking.

What about codes the dataset doesn't have? You still get a row: found: false with the reason, and for a manufacturer-range code that OEM Complete holds for the make you name (or for any make, when you name none), the makes that have codes in that range plus a link to license it.

Can I get the whole thing as a ready-made dataset? Yes — the full MechanicDB (CSV + Parquet + SQLite, commercial license, instant download) is available at mechanicdb.dataengineered.io, with a free 90-code sample (SAE + OEM) on GitHub and Kaggle.

License for results

Results are licensed for lookup use: you may use them inside your own apps, services, reports and internal workflows. You may not resell, publish or redistribute the results as a dataset, or use repeated runs to rebuild MechanicDB. Bulk and redistribution rights come with the dataset license: mechanicdb.dataengineered.io/license.

⚠️ Safety: repair steps are educational reference material, not a substitute for the vehicle manufacturer's service manual. High-voltage (hybrid/EV) and SRS/airbag work calls for the manufacturer's safety procedure whatever the difficulty rating; if you cannot follow it, leave the work to a qualified technician.

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Keywords: OBD-II decoder, DTC lookup, check engine light, trouble code database, car diagnostic API, P0420 fix, repair cost estimate, automotive repair data, OEM diagnostic codes, mechanic API.

Permanent references are opt-in with include_identity: true. They include qualified code/fix/part references and the immutable data release ID. Default results and first-listed procedure ordering stay compatible. A month string alone cannot identify a historical entity.