The pattern
A fault is injected, the script waits a fixed number of milliseconds, then checks a signal or diagnostic state. The result is flaky: sometimes the expected reaction is present, sometimes it is not, and the first instinct is to increase the wait.
That often hides the real problem. A deterministic test needs to model the timing contract: trigger point, configured debounce, signal cycle time, communication latency and an explicit measurement tolerance.
What changed the result
Instead of treating time as an arbitrary delay, the test flow was structured around observable states: establish nominal behaviour, inject one controlled condition, wait for the requirement-defined reaction window, verify the expected state, recover the input and verify the reset criterion.
The useful lesson is broader than one ECU: every fixed wait in a qualification script should have a reason. If the reason cannot be traced to software behaviour, bus timing, hardware settling or a test-system limitation, it is probably technical debt.
Reusable checklist
- Separate ECU debounce from test-tool and bus latency.
- Define the trigger edge and the observation point explicitly.
- Use a bounded tolerance rather than an unexplained oversized wait.
- Verify recovery/reset criteria, not only fault detection.
- Report actual versus expected timing so failures are diagnosable.
Apply the pattern
Is this happening in your program?
Describe the current environment and the bottleneck. We can turn it into a bounded verification or automation scope instead of starting with a generic consulting package.