★★★★★
"Finally a free alternative to ISTA that actually reads my E90's fault memory without a subscription. The live gauges alone are worth it."
BeeEmUu v5.0.0 is here
Read the release notes →
GPL-3.0 · Rust core · Tauri 2 · Python API
High-Performance BMW Diagnostics.
Powered by Rust & Tauri 2.
An open-source, ultra-fast desktop suite engineered for real-time ECU telemetry, OBD-II logging, and deep module diagnostics. Zero bloat, zero compromise.
Cross-Platform · Win / Mac / Linux
Latency <8ms
100% Open Source
beemuu — live session · E90 335i · K+DCAN
LINK OK
$ beemuu connect --iface k+dcan --baud 500k
✓ K-Line handshake OK (6.2 ms)
✓ ECU identified: MSD80 · DME 8F3A21
— streaming telemetry @ 42 Hz ———————————
$ beemuu dtc read --module all
29F1Fuel pump relay — shadow · cleared
30FFBoost dev. — intermittent · logged
▮ awaiting input_
// System Architecture
Three layers. One purpose: speed you can trust on a live vehicle.
BeeEmUu is engineered like the cars it diagnoses — every layer has a single, well-defined job, and timing-critical paths never touch a garbage collector or a browser event loop.
Core — Rust
Hardware abstraction layer driving sub-millisecond OBD-II, K-Line and CAN-BUS communication. Async Tauri commands keep the FTDI latency timer at 1 ms and ISO-TP reassembly per ISO 15765-2 off the UI thread.
let frame = isotp::send(0x22F190).await?;
Shell — Tauri 2
A lightweight native shell rendering HTML5 web views through the OS webview — roughly 50× lighter than Electron. Multi-window support, native menus, and a memory footprint under 60 MB.
bundle: 9.4 MB · ram: <60 MB
API — Python
A stdlib-only, read-only API powering community diagnostic scripts, DTC seeds, vehicle profiles and parameter extensions — no runtime dependencies. The public catalog is served as static pages from this site.
GET /v1/dtc/29F1 → 200 OK
// Core Capabilities
Everything a modern BMW workshop needs. Nothing it doesn't.
Ultra-Low Latency Telemetry
Direct hardware polling with no Java or legacy runtime in the data path. Round-trips measured in single-digit milliseconds.
Fault Code Diagnostics
Read, interpret, and clear manufacturer-specific BMW shadow codes across every module — with plain-English descriptions.
Custom Python Scripting
Write your own diagnostic routines and live telemetry processors against a clean, documented Python API.
ECU Parameter Logging
Stream dozens of sensor channels simultaneously into lightweight JSON or CSV logs for post-drive analysis.
Modern Native Shell
Multi-window support, dark-mode interface, and under 60 MB of RAM. It feels like it belongs on your OS.
Transparent & Community-Driven
Fully open source — built with independent shops and BMW enthusiasts, auditable line by line.
// What No Other Tool Does
Every other scanner asks a module a question once. BeeEmUu keeps the answers.
A DME will tell you how many times cylinder 3 misfired. It will never tell you when — and the “when” is the diagnosis. These are the features built around that idea. Read-only, open source, and honest about their confidence.
Misfire Pattern Recognition
Correlates every misfire with the RPM, load, temperature and knock values that were true at that instant — then tells you whether the pattern points at ignition, injection, detonation or a vacuum leak. Under eight events it declines to guess.
v3.0 · read-only
Adaptation Drift Tracker
Long-term fuel trims and idle learnings start moving months before a code is ever set. This trends them across sessions and projects when a value will cross its limit. Two readings are reported as not enough, not as “stable”.
v3.0 · read-only
Tuning Fingerprint Detector
Detects a non-stock calibration from read-only evidence, comparing each engine region against a community-published stock baseline. It reports what deviated and by how many standard deviations — it never names a tuning platform, because that is a claim the data cannot support.
v3.0 · read-only
Flash History Auditor
A flash counter that moved between two of your own snapshots is proof. This reconstructs each module’s programming history from the snapshots you already saved — the most valuable diagnostic data on a used car, and the one nobody shows you.
v3.0 · no live session
Symptom Index
Owners describe symptoms, not codes. Type “it stumbles when it’s cold” and get the shortlist of codes and components that actually cause it, plus what to check first. It shortlists; it does not diagnose.
v3.0 · offline
Cold Start Auto-Logger
The intermittent cold-start fault happens on the drive to work, and by the time the car is on a lift it never happens again. Arm it before you leave; the capture window opens itself and the log is there in the morning.
v3.0 · automatic
Signal Library
Every decodable signal across every supported engine, in one searchable index — with an honest grade for each. Standard OBD-II PIDs are verified by design; anything on an unpublished local identifier is labelled unverified, because trusting it blindly means chasing a fault that isn’t there.
v3.0 · 40+ signals
Vehicle Passport
One portable file per car: profile, DID map, fault data, wiring, service and adaptation history. The VIN is never included, and there is no option to include it — only a salted fingerprint so you can recognise your own car.
v3.0 · privacy-first
Parameter Hunt
No open-source KWP2000 identifier table exists for any E-series DME; every table in existence was built by somebody in a parking lot watching which bytes move. This turns that work into a community sport — and nothing scores unless you say which car it was on.
v3.0 · community
Nothing here writes to your ECU.
Every feature above is read-only analysis. Coding, flashing and calibration writes are not built and are not planned for this release — they are safety-critical and legally sensitive, and a tool that quietly ships them is a tool you cannot trust with the rest.
// Try It In Your Browser
Live gauges, simulated CAN frames.
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Demo runs in your browser via frontend/live_gauges.js. Source of truth for the byte patterns is the Rust simulator in src-tauri/src/transport/sim.rs::broadcast_frames_at; the public-site mirror and the desktop-app mirror are pinned to byte-for-byte parity by frontend/live_gauges.test.js. Real-car scales need E46 verification — see docs/validation/can-broadcast.md.
// Screenshots
See it in action.
Real screenshots of BeeEmUu running against the built-in E90 simulator.
// Community
What the community says.
★★★★★
"The walkthrough JSON export is a game-changer. I hand a diagnostic session to my indie mechanic and they know exactly what to check."
★★★★☆
"Open source, no account, no telemetry. It's the tool I reach for before paying for a dealer scan."
Reviews are community-submitted. BeeEmUu is free and open source — share your experience.
// Live Telemetry
Watch the car think — in real time.
Stream high-rate sensor channels into live graphs, decode DTCs the moment they fire, and run flash-protection checks before a single byte is written.
- Live graphing — multi-channel rendering at 60 fps with per-channel scaling and pause/rewind.
- Instant DTC decode — community-seeded definitions resolve codes to causes and fixes on read.
- Flash-protection checks — battery voltage, keep-alive cadence and session state verified before any write path unlocks.
telemetry · boost + rpm · 42 Hz
REC
42 Hz
Sample rate
6.1 ms
K-Line RTT
0
Dropped frames
// Quick Start
From clone to connected in minutes.
# Debian / Ubuntu — Tauri system deps
$ sudo apt-get install -y libglib2.0-dev libgtk-3-dev libwebkit2gtk-4.1-dev \
libayatana-appindicator3-dev librsvg2-dev libudev-dev
$ git clone https://github.com/ohgeeceee/beemuu.git && cd beemuu
$ cargo tauri dev
# Windows 10/11 — grab the signed installer
> winget install beemuu
# K+DCAN: install FTDI VCP drivers, set Latency Timer → 1 ms
$ brew install --cask beemuu
# or download the universal .dmg from Releases
# Rust 1.78+ required
$ git clone https://github.com/ohgeeceee/beemuu.git && cd beemuu
$ cd src-tauri && cargo test
$ cargo tauri build
E-series via K+DCAN (FTDI) · F/G/I-series via ENET — DoIP auto-discovery on UDP 13400
Keep BeeEmUu free.
BeeEmUu is 100% free, open source (GPL-3.0), with no paid tier, no account, and no telemetry. If it saves you a dealer scan, consider a one-time donation to keep development going.
Ready to upgrade your
diagnostic workflow?
Free forever. Open source forever. Built for the people who actually turn the wrenches.