Free EV diagnostic knowledge base

Understand EV diagnostic codes,
warnings and what to do next

Search DTCs, OEM service codes and driver-facing warning messages across modern electric and plug-in hybrid vehicles. Results connect each code to vehicle applicability, source evidence, practical context and supporting video guides when a sufficiently relevant video is available.

14,193public code pages
2062021+ EV model families with public evidence
2,565verified diagnostic entries
40EV brands with public evidence
Browse by brand

Popular EV manufacturers

Choose a manufacturer to browse the EV model families and diagnostic evidence currently available in the database.

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Tesla Model 3 electric vehicleTesla Model 3

Tesla

5 EV model families currently cataloged, with diagnostic coverage growing as new OEM and regulator evidence is verified.

229 verified152 accepted research
Chevrolet Blazer EV electric vehicleChevrolet Blazer EV

Chevrolet

6 EV model families currently cataloged, with diagnostic coverage growing as new OEM and regulator evidence is verified.

255 verified7 accepted research403 reference candidates
Ford Mustang Mach-E electric vehicleFord Mustang Mach-E

Ford

3 EV model families currently cataloged, with diagnostic coverage growing as new OEM and regulator evidence is verified.

150 verified15 accepted research413 reference candidates
Volkswagen ID.4 electric vehicleVolkswagen ID.4

Volkswagen

15 EV model families currently cataloged, with diagnostic coverage growing as new OEM and regulator evidence is verified.

37 verified5 accepted research528 reference candidates
Cadillac LYRIQ electric vehicleCadillac LYRIQ

Cadillac

4 EV model families currently cataloged, with diagnostic coverage growing as new OEM and regulator evidence is verified.

133 verified5 accepted research402 reference candidates
Lincoln Aviator PHEV electric vehicleLincoln Aviator PHEV

Lincoln

2 EV model families currently cataloged, with diagnostic coverage growing as new OEM and regulator evidence is verified.

4 verified413 reference candidates
GMC HUMMER EV electric vehicleGMC HUMMER EV

GMC

2 EV model families currently cataloged, with diagnostic coverage growing as new OEM and regulator evidence is verified.

8 verified5 accepted research402 reference candidates
Audi Q4 e-tron electric vehicleAudi Q4 e-tron

Audi

18 EV model families currently cataloged, with diagnostic coverage growing as new OEM and regulator evidence is verified.

272 verified11 accepted research128 reference candidates
Chrysler Pacifica Hybrid electric vehicleChrysler Pacifica Hybrid

Chrysler

1 EV model family currently cataloged, with diagnostic coverage growing as new OEM and regulator evidence is verified.

28 verified283 reference candidates
BMW iX electric vehicleBMW iX

BMW

14 EV model families currently cataloged, with diagnostic coverage growing as new OEM and regulator evidence is verified.

41 verified14 accepted research250 reference candidates
BYD ATTO 3 electric vehicleBYD ATTO 3

BYD

15 EV model families currently cataloged, with diagnostic coverage growing as new OEM and regulator evidence is verified.

302 verified
Mazda MX-30 electric vehicleMazda MX-30

Mazda

3 EV model families currently cataloged, with diagnostic coverage growing as new OEM and regulator evidence is verified.

33 verified233 reference candidates

Representative vehicle photography is used for visual identification. View image credits and licenses →

Built for real diagnostic questions

More than a list of fault codes

Find the exact code

Search is case-insensitive and understands common separator variations. OEM formats such as BMS_a066, BMS-a066 and BMS a066 can resolve to one canonical diagnostic page instead of creating duplicate pages.

See where it applies

Diagnostic pages show the manufacturer and model-family applicability supported by our evidence. We keep model applicability separate from generic code definitions so a code is not presented as vehicle-specific without support.

Understand the evidence

Each page distinguishes verified manufacturer or regulator evidence from accepted research and reference material. Unknown causes, repair steps, recalls or safety conclusions are not filled in merely to make a page look complete.

Prepare for service

Pages organize the verified information into clear sections covering meaning, affected system, seriousness, driving and charging considerations, safe actions, troubleshooting context, service checks, related bulletins and sources.

Quality first

Three evidence levels

Reference entries provide useful code context from openly available technical datasets. Accepted research entries are curated findings that may still need stronger manufacturer-level evidence. Verified entries are tied to source evidence and applicability checks before they are treated as canonical diagnostic data.

This matters because the same-looking code can mean different things across systems, model years or manufacturers, and an internet discussion is not equivalent to an OEM service document.

How verification works →
Transparent by design

Sources remain visible

Diagnostic pages are server-rendered and designed to be readable by people and search systems. Canonical URLs, structured data, source labels and model relationships are kept visible rather than hiding the evidence behind a login or an opaque score.

When we do not have enough evidence for a cause, repair procedure, TSB relationship or recall, the page says so instead of inventing an answer.

See our data sources →
A growing EV knowledge base

Coverage expands as evidence becomes available

EV diagnostic information is fragmented across owner manuals, service bulletins, regulator records, repair documentation and manufacturer-specific alert systems. We continuously organize those sources into searchable manufacturer, model and diagnostic relationships while preserving source provenance.

The database includes conventional OBD/DTC identifiers as well as OEM-specific diagnostic codes and driver-facing warning messages when the source establishes that they are diagnostic in nature. New entries are not added simply to reach a numerical quota.

On a diagnostic page you may find:
  • Quick answer and technical explanation
  • Affected system and seriousness
  • Symptoms and evidence-backed possible causes
  • Drive and charge guidance where established
  • Safe next steps and service context
  • Model applicability, TSBs and recalls
  • Related codes and FAQs
  • Verified sources and supporting videos