OBDonUDS - SAE J1979-2 - Protocol Stack

200+

Customers Supported Since 2010

100+

Scalable & Reusable Bootloader Platforms Delivered

30%

Quicker Time-to-Market Enabled

95%

Reduced Development Time using PC-Based Automation

Enabling UDS-Based On-Board Diagnostics for Vehicle ECUs

SAE J1979-2, also known as OBDonUDS, defines standardized communication between a vehicle's on-board diagnostics system and an external UDS-based test equipment.

Unlike classic OBD-II diagnostics, OBDonUDS uses ISO 14229 Unified Diagnostic Services to access emissions-related diagnostic data. It helps vehicle manufacturers transition from legacy OBD modes to a more scalable diagnostic architecture that can support modern ECUs, CAN FD networks, centralized vehicle architectures, and evolving regulatory OBD requirements.

Embitel's SAE J1979-2 OBDonUDS Protocol Stack

Ready-to-integrate SAE J1979-2 software stack for automotive ECU programs.
Supports OEMs, Tier-1 suppliers and engineering teams.
Pre-tested library reducing development time by up to 50%.
Supports migration from classic SAE J1979 / ISO15031 diagnostics.
Maintains OEM-specific architecture and fault memory strategy.
Available as an easy-to-integrate library.

Our Services

Embitel's Service Offerings for SAE J1979-2 OBDonUDS Integration

OBDonUDS Stack Integration for Automotive ECUs

Integration of SAE J1979-2 OBDonUDS stack with ECU application software
UDS diagnostic architecture design and implementation
Integration with Diagnostic Event Manager and fault-memory modules
DTC mapping, status-bit configuration, and emissions-related fault handling
Configuration of snapshot records and extended data records
Support for functional and physical diagnostic addressing
CAN and CAN FD transport layer integration
Diagnostic timing, session, communication, and response handling configuration

OBDonUDS Stack Development and Customization

Development of project-specific OBDonUDS services
Custom diagnostic data handling for ECU-specific requirements
Integration of OEM-specific diagnostic identifiers and data records
Fault-memory design for emissions-related diagnostic events
Support for diagnostic event monitoring and debounce strategy
Configuration of I/M readiness, monitor status, and vehicle information functions
Integration with existing UDS server, bootloader, and diagnostic middleware

AUTOSAR OBDonUDS Integration

Integration with AUTOSAR DCM, DEM, FIM, CAN TP, and COM stack
Configuration of UDS services required for OBDonUDS implementation
DTC event configuration and Diagnostic Event Manager mapping
Integration of OBDonUDS functionality with AUTOSAR ECU software
Support for Classic AUTOSAR and customized diagnostic architectures

OBDonUDS Testing and Validation

Unit testing and integration testing of OBDonUDS functionality
CAN and CAN FD communication validation
DTC, snapshot, and extended data verification
UDS service validation and negative-response testing
Functional-addressing and physical-addressing validation
Test automation support using CANoe, diagnostic testers, and custom test tools
Diagnostic trace analysis and defect resolution support

KEY CAPABILITIES

Key Capabilities of the SAE J1979-2 Stack

SAE J1979-2 OBDonUDS Support

Supports standardized OBDonUDS diagnostic communication based on SAE J1979-2 and ISO 14229 UDS services.

UDS-Based Diagnostic Architecture

Leverages a common UDS diagnostic framework for emissions-related OBD functions, ECU diagnostics, flashing, security access, routine control, and fault-memory management.

DTC and Fault Memory Accesss

Supports access to emission-related Diagnostic Trouble Codes, DTC status information, snapshot records, extended data records, and ECU-specific fault-memory information.

I/M Readiness and Monitor Data

Enables support for inspection and maintenance readiness information, monitor status, monitor completion data, and in-use performance-related parameters as applicable to the ECU program.

Vehicle Information Services

Enables standardized access to vehicle information and identification-related data required for diagnostic communication.

CAN and CAN FD Support

Integrates the OBDonUDS stack over ISO 15765 transport layers for CAN and CAN FD based vehicle networks.

AUTOSAR and Non-AUTOSAR Integration

Supports integration with AUTOSAR Diagnostic Communication Manager, Diagnostic Event Manager, CAN TP, and custom non-AUTOSAR diagnostic frameworks.

Configurable ECU Integration

Configures diagnostic identifiers, DTC mapping, fault-memory behaviour, communication parameters, timing values, ECU addressing, and diagnostic data handling based on program requirements.

Why Move from OBD-II to OBDonUDS?

Classic OBD-II uses standardized diagnostic modes and PIDs to expose emissions-related vehicle data. SAE J1979-2 moves these functions to a UDS-based diagnostic architecture.

This transition enables automotive programs to:

Align emissions-related OBD functions with the ECU's broader UDS diagnostic framework

Support richer DTC, snapshot, extended-data, and monitor-status reporting

Reduce duplication between conventional ECU diagnostics and regulatory OBD diagnostics

Prepare diagnostic software for CAN FD, Ethernet-enabled architectures, and centralized vehicle computing

Build a scalable path toward future diagnostic standards, including ZEVonUDS for electric vehicle propulsion systems

OBDonUDS is not simply a conversion of classic OBD modes into UDS services. It introduces a more structured diagnostic model for fault memory, monitor data, vehicle status, and standardized diagnostic reporting.

Talk to Embitel's Automotive Diagnostics Team

Discuss your OBDonUDS implementation requirements with our experts.

OBDonUDS Applications Across Automotive Programs

Engine and Powertrain ECUs

Implement standardized emissions-related diagnostics for engine control units, transmission control units, hybrid control units, exhaust after-treatment controllers, and related powertrain ECUs.

Hybrid Vehicle Controllers

Support OBDonUDS diagnostic requirements across hybrid powertrain components, including engine, motor control, energy management, and transmission-related ECUs.

Gateway and Central Diagnostic Controllers

Implement diagnostic routing, centralized fault data collection, and OBDonUDS communication support in gateways and centralized vehicle controllers.

Commercial Vehicle ECUs

Support UDS-based OBD diagnostic architectures for commercial vehicle applications where ECU diagnostics, emissions-related monitoring, and scalable network communication are required.

Vehicle Diagnostics and Validation Tools

Support development of diagnostic tester applications, engineering tools, validation frameworks, and ECU simulation environments that need to communicate with SAE J1979-2 compliant ECUs.

Architecture

SAE J1979-2 OBDonUDS Stack Architecture

UDS Layer

ISO 14229 diagnostic services, diagnostic sessions, request handling, response generation, error handling, and diagnostic communication management.

Application Layer

ECU application software, emission monitoring functions, diagnostic event reporting, vehicle status logic, and fault detection functions.

OBDonUDS Layer

SAE J1979-2 compliant diagnostic functions for DTC reporting, status information, snapshots, extended data, monitor information, and vehicle data.

Hardware Abstraction

MCU-specific CAN drivers, transceiver integration, operating system abstraction, and board support package interfaces.

Transport Layer

ISO 15765-2 transport protocol for segmented diagnostic communication.

Network Layer

CAN and CAN FD communication based on ISO 15765-4 requirements.

TECHNICAL COVERAGE

Technical Coverage of Embitel's SAE J1979-2 OBDonUDS Stack

Layer	Supported Technology
OBDonUDS Application Layer	SAE J1979-2
Diagnostic Services	ISO 14229 UDS
Transport Protocol	ISO 15765-2
Network Communication	ISO 15765-4 CAN / CAN FD
ECU Diagnostics	DTCs, snapshot data, extended data, monitor status, vehicle information
ECU Frameworks	AUTOSAR and non-AUTOSAR
Integration Environment	RTOS, bare-metal, and MCU-based automotive ECUs
Test Support	CANoe, diagnostic testers, custom test tools, trace analysis

Embitel’s
Advantage

Embedded Diagnostics Expertise

Embitel has extensive experience in automotive diagnostic stack development, including UDS, DoIP, OBD‑II, J1939 diagnostics, bootloader integration, DTC handling, and ECU communication stack integration.

Ready‑to‑Integrate Stack Architecture

The OBDonUDS stack is designed for faster integration into production ECU software while allowing project‑specific configuration and adaptation.

Configuration and Customization Support

The stack can be configured for ECU‑specific DTC handling, diagnostic identifiers, snapshot records, monitor data, transport settings, and OEM diagnostic requirements.

Integration Beyond the Protocol Layer

Support extends beyond protocol delivery. Embitel can assist with ECU architecture, AUTOSAR integration, diagnostic design, fault‑memory strategy, CAN communication, validation, and maintenance.

Support for Legacy and Future Diagnostic Programs

Teams working with conventional OBD‑II can receive migration support toward SAE J1979‑2 OBDonUDS while retaining legacy compatibility where required.

Ready for Production

Build a Future-Ready OBD Diagnostic Architecture

Implement SAE J1979-2 OBDonUDS diagnostics with a configurable embedded protocol stack and engineering support across design, integration, validation, and maintenance.

Talk To Our Experts

FAQs

Frequently Asked Questions

SAE J1979-2 is the OBDonUDS diagnostic standard. It defines how an external diagnostic tester communicates with a vehicle�s on-board diagnostics system using UDS-based diagnostic services.

Classic OBD-II uses standardized diagnostic modes and PIDs. OBDonUDS uses ISO 14229 UDS services to provide standardized OBD functions with a more structured approach to DTCs, snapshot data, extended data, vehicle status, and monitor information.

Yes. The stack can be integrated over CAN and CAN FD based communication architectures, depending on ECU and vehicle-network requirements.

Yes. The stack can be integrated with AUTOSAR components such as DCM, DEM, FIM, CAN TP, COM stack, and ECU-specific application software.

Yes. OBDonUDS functions can be integrated with an existing UDS diagnostic server so that regulatory OBD functions and general ECU diagnostics operate within a common diagnostic architecture.

Source code access can be provided based on the commercial agreement and project requirements.

Yes. Embitel can assess the existing OBD-II implementation, map legacy diagnostic functions, define the target OBDonUDS architecture, and support implementation and validation.

Yes. Embitel provides support for unit testing, integration testing, diagnostic validation, CAN communication testing, trace analysis, and test automation.

SAE J1979-2 OBDonUDS Protocol Stack