A module may remain responsive when disconnected from a faulty load. That can help narrow an investigation, but it does not establish whether the problem is in the load, harness or driver.

Interpreting the evidence

Compare the behaviour under an approved representative test condition and investigate the vehicle circuit separately. Check current demand and voltage drop when the symptom occurs. A complete repair needs a reason why the output failed under its normal operating conditions.

Keep this evidence

Send the connected load details and the difference between connected and disconnected behaviour.

Unloaded operation is a limited result. It should not be presented as proof that every module function has passed.

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.