Knowledge Base
Last Updated: 2026-07-30
A 0x8002 acknowledgement proves that the DoIP entity accepted the diagnostic message. It does not prove the request reached a vehicle bus or that an ECU received or answered it.
Say ‘no final UDS response observed within the evidence window’, not ‘the ECU did not respond’.
Exclude capture loss, reassembly errors, and response traffic outside the retained window before using this diagnosis.
Compare an equivalent serial run that has the same DoIP acknowledgement followed by a final positive UDS response.
The comparison is evidence of different observed outcomes, not proof of a single parallel-mode root cause.
Final Diagnosis
Confidence
High for the retained tester-side observation
Likely Root Cause
Not determined: gateway internal processing, bus forwarding, bus transport, and target ECU response remain open
Primary Evidence
EVID-RA-ACK-NO-FINAL-UDS-01 and EVID-RA-ACK-FINAL-UDS-POSITIVE-CONTROL-01
Recommended Next Check
Collect synchronized gateway and bus-side evidence for the same request window.
Each example identifies whether it is a controlled simulator observation or a redacted field-evidence window. The evidence record bounds what the sequence can and cannot establish.
Parallel run
Evidence reference: EVID-RA-ACK-NO-FINAL-UDS-01
The DoIP entity acknowledges two comparable diagnostic attempts, while no matching final UDS response is observed before the retained window ends.
Evidence signals
Real Timeline
The boundary is after DoIP acceptance, not conclusively at the ECU.
Serial positive control
Evidence reference: EVID-RA-ACK-FINAL-UDS-POSITIVE-CONTROL-01
A serial control receives the DoIP acknowledgement and a final positive UDS response shortly afterward.
Evidence signals
Real Timeline
It prevents treating every acknowledged request as an inevitable no-response case.
A visual sequence helps confirm whether the session actually progressed, stalled, or broke after the visible tool symptom.
Tester
RA 0x10 and diagnostic request
DoIP entity
0x8002 acknowledgement
Downstream path
Final UDS response observed or absent in window
These packet-level checkpoints are the smallest proof units behind the article narrative.
RA response
DoIP entity -> tester
0x0006 code 0x10.
Routing control path is active.
Diagnostic acknowledgement
DoIP entity -> tester
0x8002 / code 0x00.
Entity accepted the diagnostic message.
Observation horizon
downstream path
Final UDS response appears in the control but not the parallel retained window.
Requires gateway/bus evidence for further localization.
This is the condensed engineering verdict the analyzer would put in front of the operator.
No final UDS response observed within the evidence window after DoIP acceptance.
No final UDS response observed within the evidence window after DoIP acceptance.
Do not claim forwarding, ECU receipt, or root cause without synchronized downstream evidence.
Do not claim forwarding, ECU receipt, or root cause without synchronized downstream evidence.
These are cases where the tool symptom can point in the wrong direction unless the packet timeline is checked.
Symptom: The tool says ECU no response.
Packet truth: Only the absence of a final UDS response in the retained tester-side window is proven.
Risk: The fault is over-located to the ECU.
Symptom: 0x8002 is treated as bus forwarding confirmation.
Packet truth: It is an entity-boundary acknowledgement.
Risk: Gateway-side and bus-side checks are skipped.
Use this order in real troubleshooting so packet evidence narrows the branch before repair effort expands.
These are the interpretation traps that real packet evidence helps avoid.
Use nearby guides to move from protocol filtering to root-cause troubleshooting without leaving the knowledge base.
No. It confirms acceptance at the DoIP entity boundary.
Only to the downstream path after DoIP message acceptance; synchronized gateway and bus evidence is still required.
Best when the tool reports no ECU response after a successful Routing Activation.
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