A fixed scan value may indicate a real circuit problem, a substituted value or an unsupported parameter. It does not automatically prove the sensor element has stopped responding.
Establish which value is displayed
Record the parameter name, tool and related codes. Ask the workshop whether the controller uses a fallback value under the current fault conditions. Compare the result with the relevant circuit measurement where the approved procedure calls for it.
Do not replace the ECU because a scanner graph is flat. The technician should distinguish the measured input from processed or substituted data. Preserve the conditions under which the physical change was established so the comparison is meaningful and does not rely on an assumed change that was never independently confirmed.
Need help with this fault?
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