An electronic output can perform different checks when it is on and when it is off. A fault reported in one state may not be reproduced by a simple powered test.

What to check next

Confirm when the diagnostic runs and whether the fitted load matches the vehicle specification. Check connections and previous accessory modifications. Compare the actual state with the manufacturer’s fault criteria before deciding that the module has incorrectly detected an open circuit.

Useful information for an enquiry

Send the full fault record and whether the original lamp, motor or valve is still fitted.

Low-current replacement lamps and added electronics can change circuit behaviour. Do not defeat monitoring with improvised loads as a substitute for diagnosis.

Speak to AXION

For ECU testing and component-level repair, 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.