AutoDecoder Workbench

A C# and .NET WinForms application for decoding, classifying, and analyzing automotive diagnostic logs containing ISO-TP traffic, UDS requests and responses, XML DID data, raw hexadecimal payloads, and ASCII output.

The workbench converts mixed log content into structured objects so engineers can review protocol behavior, identify negative responses, summarize DID activity, and compare raw evidence with decoded results.

Core Capabilities

• Line-by-line protocol classification
• ISO 15765 and ISO-TP message reconstruction
• UDS request and response interpretation
• Positive and negative response decoding
• DID and NRC summary counts
• XML diagnostic response parsing
• Raw and decoded split view
• Search and UDS-only filtering
• Multiple analysis sessions
• Stable, null-safe WinForms rendering

Architecture

AutoDecoder.Gui        WinForms presentation layer
AutoDecoder.Models     Strongly typed diagnostic domain models
AutoDecoder.Protocols  Deterministic protocol parsing and decoding

Models

Each input line is represented by a domain type derived from an abstract LogLine base class:

• Iso15765Line
• XmlLine
• HexLine
• AsciiLine
• UnknownLine

This design keeps raw evidence encapsulated while allowing each line type to implement its own parsing behavior.

Protocol Components

• LineClassifier
• Iso15765Decoder
• UdsDecoder
• XmlDidDecoder
• HexTools
• DecodeTables

Example Patterns

ISO-TP and UDS Traffic

ISO15765 TX -> [00,00,07,D0,22,80,6A]
ISO15765 RX <- [00,00,07,D8,7F,22,78]

Negative Response

7F 22 78

Decoded as a negative response to ReadDataByIdentifier with NRC 0x78, Response Pending.

Positive Response

62 F1 88 ...

Decoded as a positive ReadDataByIdentifier response for DID 0xF188.

Supported UDS Services

SID	Service
0x10	Diagnostic Session Control
0x11	ECU Reset
0x22	Read Data by Identifier
0x27	Security Access
0x2E	Write Data by Identifier
0x31	Routine Control
0x3E	Tester Present

Supported Negative Response Codes

0x10, 0x11, 0x13, 0x22, 0x31, 0x33, 0x35, 0x36, 0x37, and 0x78.

User Interface

Main Decoded View

Raw and Decoded View

NRC and DID Summary

Data Handling Boundary

This public repository must use only synthetic or fully sanitized diagnostic data.

Do not commit VINs, customer information, real OEM logs, internal endpoints, software records, firmware, calibration files, credentials, or proprietary diagnostic specifications.

The decoder provides engineering assistance only. Results require validation against approved diagnostic requirements and source evidence.

Technical Details

• Language: C#
• Framework: .NET 10
• Interface: WinForms
• Architecture: Layered models, protocols, and presentation
• Status: Active development

Engineering Direction

Planned improvements include CAN identifier flow tracking, UDS conversation grouping, enhanced NRC visualization, exportable findings, large-log performance improvements, and DoIP support.

Portfolio Positioning

This project demonstrates automotive diagnostic-domain knowledge, embedded communication analysis, object-oriented software design, deterministic decoding, and engineering-focused user-interface development.

Author

Harold L. R. Watkins

Automotive Cybersecurity Engineer | Embedded Systems | Vehicle Software Verification