by Serial Data Pro · Big Dog Diagnostics

OmniPass

Every protocol on the bus — decoded & explained by AI.

A proprietary vehicle-diagnostic pass-through with an AI brain. Custom hardware clips onto the DLC and captures classic CAN and CAN-FD off the raw differential bus, then decodes every standard service on top — OBD-II Modes 01–0A, UDS (ISO 14229), J1939 — down to DTCs, live PIDs, monitor results, VIN, and module memory. Then an onboard AI reads the raw bytes for you and answers in plain English. Owned end to end — silicon, firmware, protocol stack, and the intelligence that runs it.

CAN · ISO 11898 CAN-FD · 5 Mbit/s OBD-II · Modes 01–0A UDS · ISO 14229 J1939 · Heavy-duty EEPROM · All families JTAG · Chip-level
// when another tech asks: "what protocols does it speak?"

The honest answer is all of them — every service that rides the CAN bus, plus the raw memory underneath it.

Most scan tools speak a fixed slice of one standard through someone else's pass-thru. This captures the raw bus itself — protocol-agnostic at the frame level — then decodes each standard service on top: OBD-II, UDS, J1939. If the vehicle sends it, the bus carries it, and the AI reads it. There's no "unsupported protocol" list, because it isn't decoding through a vendor's fixed menu — it's reading the wire.

Straight off the wire

OmniPass reads the differential pair itself — CAN-High and CAN-Low, mirror signals whose ~2 V split is every bit on the bus. A live dominant / recessive capture:

CAN-H · 3.5 V dominant CAN-L · 1.5 V dominant 2.5 V recessive (idle) D = dominant · R = recessive

The signal chain

Owned at every layer — the silicon, the firmware, the transport, the server, and the AI that reads it. No licensed pipe, no vendor lock.

01 · Capture

DLC Unit

Clips onto the vehicle connector, powered from the port. Reads CAN & CAN-FD off the differential pair in real time.

ESP32 · CAN transceiver
OBD-II pin 6/14
02 · Sniff & log

Sniffer

Dual controllers cover classic CAN and CAN-FD. Timestamped, geo-tagged, buffered to onboard EEPROM.

MCP2515 + MCP2518FD
DS3231 RTC · 24C64 · GPS
03 · Uplink

Server

Frames stream into a private ingest, held live and replayable. Where raw bytes meet the decoders.

BLE mesh → Wi-Fi
/api ingest
04 · Decode

Kate · the AI

Raw frames become plain English — what each ID is, what each service means, what a code is telling you and where to look. The intelligence that makes the whole bus readable.

OBD-II · UDS · J1939
Hermes 405B + RAG
DLC ─────▶ SNIFFER ─────▶ SERVER ─────▶ AI

What it reads

Every service on the CAN bus — decoded from real captured frames, never simulated. Plus the bench-level memory most tools can't touch.

OBD-II SAE J1979

  • Mode 01Live data PIDs — RPM, coolant, MAF, trims
  • Mode 02Freeze-frame snapshot at fault
  • Mode 03Stored trouble codes
  • Mode 04Clear codes & monitors
  • Mode 06On-board monitor test results
  • Mode 07Pending codes
  • Mode 09VIN · Calibration IDs · CVN
  • Mode 0APermanent codes

UDS ISO 14229

  • 0x10Diagnostic session control
  • 0x27Security access — seed / key
  • 0x22Read data by identifier
  • 0x2EWrite data by identifier
  • 0x2FInput / output control (actuators)
  • 0x31Routine control
  • 0x19Read DTC information
  • 0x3ETester present

Bus & Fleet ISO 11898 · J1939

  • CANClassic high-speed, 11-bit & 29-bit
  • CAN-FDFlexible data-rate, up to 64-byte frames
  • J1939Heavy-duty — PGN / SPN, address claim
  • RawEvery frame on the wire, decoded or logged

Beneath the bus Bench · Memory

  • EEPROMAll families — I²C 24-series, SPI 25-series, Microwire 93-series & parallel; full module dumps
  • JTAGBoundary-scan & on-chip debug — direct MCU / flash access
  • ImmoPIN / CS / seed-key, rolling counters
  • KeyKey data, cloning, programming
  • ECMOdometer, coding & config bytes

UDS · the full service set ISO 14229

Unified Diagnostic Services runs deep — OmniPass reads the whole ISO 14229 stack off the bus, not just the common handful. Every service, grouped by function:

Session & Communication

  • 0x10Diagnostic Session Control
  • 0x11ECU Reset
  • 0x27Security Access — seed / key
  • 0x28Communication Control
  • 0x29Authentication
  • 0x3ETester Present
  • 0x85Control DTC Setting
  • 0x86Response On Event
  • 0x87Link Control

Data Transmission

  • 0x22Read Data By Identifier
  • 0x23Read Memory By Address
  • 0x24Read Scaling Data By ID
  • 0x2ARead Data By Periodic ID
  • 0x2CDynamically Define Data ID
  • 0x2EWrite Data By Identifier
  • 0x3DWrite Memory By Address

DTC · I/O · Routine

  • 0x14Clear Diagnostic Information
  • 0x19Read DTC Information
  • 0x2FI/O Control By Identifier
  • 0x31Routine Control

Upload / Download

  • 0x34Request Download
  • 0x35Request Upload
  • 0x36Transfer Data
  • 0x37Request Transfer Exit
  • 0x38Request File Transfer
  • 0x83Access Timing Parameter
  • 0x84Secured Data Transmission

Signature capability — the VE Test

Automated Volumetric Efficiency testing — a diagnostic only a handful of tools in the industry perform, built directly into OmniPass.

// is the engine actually breathing the way it should?

A guided Volumetric Efficiency test — MAF, RPM, and displacement resolved into one real breathing number.

It measures the engine's actual airflow against what it should move at a given RPM, and surfaces the restrictions that never throw a code: a plugging catalytic converter, a collapsed or restricted exhaust, an intake restriction, or a cam-timing / valve problem. It turns "runs rough, no codes" into a measured percentage a tech can act on — built in and guided, not a calculator on the side. Almost no scan tool automates it.

Why it isn't a J2534

A pass-thru is a rented, standardized pipe you bolt someone else's software onto. This does the same job — and owns the whole thing.

// OmniPass

Owned end to end — hardware, firmware, transport, server, and the AI that reads it. No license, no lock.
Reads the raw wire — no fixed "supported protocol" menu. If it's on the bus, it's captured.
AI-native — raw bytes become plain English: what the ID is, what the code means, where to look.
Honest to the frame — decodes only what's actually captured. Never fabricates a value.

// A standard J2534

A generic pipe — you supply (and license) the OEM software that speaks through it.
Bound to the J2534 API spec and whatever the connected app supports.
No intelligence — it moves bytes; a human still has to interpret them.
Interoperable, but rented — not yours, and not integrated.