A power transistor’s internal diode can take part in a motor-control circuit’s switching operation. Its behaviour matters beyond a basic diode-test result on a meter.

How to narrow it down

Identify how current circulates in the actual output stage and compare the replacement device’s relevant characteristics. Review switching losses and the surrounding driver if a repaired stage overheats. The motor, harness and mechanical load should also be checked for the cause of the original failure.

What to include with the fault report

Supply the module number, failed channel and replaced component details.

A diode-mode reading is one piece of evidence. It cannot establish that a transistor is suitable for repetitive switching in that circuit.

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