Inside a controller, an analogue signal must be sampled by an input circuit. An unsuitable source impedance or damaged input network can affect the conversion even when a slow voltage measurement looks steady.

Interpreting the evidence

A component-level assessment should compare the external signal with the input network and sampling requirements of the fitted electronics. Check for damaged filters or previous component substitutions. The aim is to explain a repeatable discrepancy between the physical input and the controller’s interpretation.

Keep this evidence

Send the symptom, measured signal and details of any earlier board repair.

This is an electronics investigation requiring the correct circuit and device information. It is not a reason to alter factory filtering or calibration experimentally.

Speak to AXION

For complex vehicle-electronics diagnostics, send your vehicle details and fault report. Workshop assessment is in Didcot, Oxfordshire. Suitable postal or remote work is confirmed before booking.

Technical background from Texas Instruments. The referenced design explains the principle; the vehicle-specific procedure determines the repair.