UDS service and session testing
Build focused tests around diagnostic sessions, DIDs, routine control, security access, positive responses, and negative responses.
Vehicle Diagnostics · UDS Testing
Test ECU diagnostic behavior with repeatable evidence
I test and troubleshoot UDS communication across diagnostic sessions, DIDs, routine control, security access, DTC handling, ISO-TP, DoIP, CAN, and CAN-FD. The work can extend an existing CANoe project or start from your ECU behavior and problem description.
Discuss a UDS ProjectProblems I can investigate
Find the behavior behind the symptom
- 01
ECU not responding
Investigate whether missing diagnostic responses relate to transport, network communication, diagnostic session state, or the ECU interaction sequence.
- 02
UDS request fails
Reproduce incomplete diagnostic requests and compare observed responses with the expected UDS flow, timing, and available diagnostic data.
- 03
Unexpected UDS negative response
Capture and analyze negative-response codes in context to identify where the request sequence, session state, or service expectations diverge.
- 04
DTC keeps returning
Trace recurring DTC behavior across clearing, subsequent requests, and related diagnostic activity without assuming the cause from the code alone.
What I can help with
Focused engineering work in Vehicle Diagnostics
Diagnostic transport checks
Check UDS exchanges over ISO-TP on CAN or CAN-FD, or over DoIP on an IP network as supported by the setup. Keep transport failures separate from UDS service-response failures.
CANoe and CAPL test automation
Create repeatable CANoe workflows and CAPL scripts for request sequences, response checks, setup, and recorded test results.
DTC and diagnostic data investigation
Use observed ECU communication, DTC behavior, DID access, and supplied diagnostic descriptions to narrow down inconsistent results.
What to send
Start with the evidence you already have
ECU
The ECU available for communication or testing, together with the diagnostic behavior that needs to be exercised.
ODX
The available diagnostic-data description for interpreting services, DIDs, and expected diagnostic content.
PDX
The packaged exchange containing the ODX diagnostic data used for the testing scope.
BLF recording
A timestamped bus communication recording for reviewing observed requests, responses, and transport behavior.
Existing CANoe project
The current CANoe configuration and project assets when the work extends an established test environment.
Problem description
Observed symptoms, reproduction steps, context, and the expected behavior to compare against test results.
How the analysis works
From recorded data to engineering findings
- 01
Define the diagnostic scope
Review the ECU, available ODX or PDX data, recordings, project assets, and problem description to establish the requests and responses that need testing.
- 02
Reproduce the observed behavior
Run the relevant diagnostic flow and capture the ECU communication, diagnostic session context, transport activity, and returned responses.
- 03
Separate communication from service behavior
Examine CAN, CAN-FD, ISO-TP, or DoIP activity alongside UDS request sequencing to narrow where the behavior differs from expectations.
- 04
Implement repeatable checks
Create focused CANoe and CAPL automation where useful, with setup, assertions, and result handling aligned to the agreed test scope.
- 05
Review evidence and findings
Summarize reproduced behavior, relevant traces, test results, and remaining uncertainty in an engineering analysis.
What you receive
Deliverables matched to the investigation
Automated test suite
Executable tests with setup, assertions, repeatable diagnostic flows, and result handling for the agreed ECU behavior.
Diagnostic application
Software for executing and interpreting the in-scope ECU diagnostic services.
CAPL script
CAPL source implementing the agreed CANoe behavior, diagnostic sequence, or automated checks.
Engineering analysis
A documented technical analysis containing evidence, reproduced behavior, findings, and unresolved points where applicable.
Technologies & formats
Automotive data and analysis environments
- UDS
Unified Diagnostic Services
ISO 14229 diagnostic services for communicating with vehicle ECUs.
- CANoe
Vector CANoe
A development, simulation, test, and analysis environment for vehicle networks.
- CAPL
Communication Access Programming Language
Vector event-driven language for network simulation, testing, and automation.
- ISO-TP
ISO 15765-2 Transport Protocol
A segmented transport protocol for messages carried over CAN.
- DoIP
Diagnostics over Internet Protocol
Diagnostic transport over IP networks as defined by ISO 13400.
- DTC
Diagnostic Trouble Code
A coded diagnostic record identifying a detected fault condition.
- DID
Data Identifier
A UDS identifier addressing diagnostic data exposed by an ECU.
- Diagnostic Session
Diagnostic Session
An ECU diagnostic operating mode controlling service availability and timing.
- Routine Control
Routine Control
The UDS service used to start, stop, or request results from ECU routines.
- Security Access
Security Access
A diagnostic challenge-response mechanism that unlocks protected ECU services.
- DCM
Diagnostic Communication Manager
The Classic AUTOSAR basic-software module handling diagnostic communication.
- CAN
Controller Area Network
A priority-based broadcast bus used for in-vehicle control communication.
- CAN-FD
CAN Flexible Data-rate
An extension of CAN with larger payloads and a faster data phase.
FAQ
Practical questions before an investigation
- Can you test an ECU when the failure is intermittent?
- Yes. A BLF recording, reproduction steps, and the available ECU context can be used to structure repeatable checks and compare successful and failing communication.
- Can the work use an existing CANoe project?
- Yes. An existing CANoe project can provide the starting configuration for extending tests, adding CAPL behavior, or reviewing current diagnostic flows.
- Do you test both CAN and DoIP diagnostic transport?
- The scope can cover CAN, CAN-FD, ISO-TP, or DoIP when the required ECU access and project context are available.
- Can you investigate recurring DTC behavior?
- Yes. The investigation can reproduce the DTC sequence, examine related diagnostic requests and responses, and document evidence without assuming a root cause in advance.
Discuss the evidence
Discuss a UDS Project
Share the ECU context, diagnostic data, recording, or problem description. I can review the scope and suggest a focused UDS testing engagement.