A new part can restore a signal without restoring the pattern the engine controller expects. Fitment, target geometry and the signal reaching the ECU all matter after mechanical work.

How to narrow it down

Preserve the before-and-after history and compare the new waveform with the specified arrangement. Check installation and connections before assuming an ECU coding problem. If the engine now cranks normally but will not synchronise, the recent mechanical work is relevant evidence rather than proof of one particular cause.

What to include with the fault report

Send the engine identification, replaced parts and a capture of the starting event.

A sensor’s ability to generate pulses does not establish correct mechanical timing or target compatibility.

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 HELLA. The referenced design explains the principle; the vehicle-specific procedure determines the repair.