How to identify an ECU from the unit itself

Almost everything needed to identify a control module is printed on the label. The difficulty is knowing which of the several numbers on it matters.

What to look for

• Manufacturer - Bosch, Continental, Siemens, Delphi, Denso, Marelli
• Hardware family - for example EDC17, MED17, SIM2K, DCM3.7
• The OEM part number - usually the longest number, often starting with the vehicle manufacturer's prefix
• The manufacturer's own number - Bosch numbers commonly begin 0281 or 0261
• A software or calibration number, where one is printed

Photographing it

If you are sending photographs for identification, a sharp, straight-on shot of the label does most of the work. Add the connector end and both faces of the housing, and any damage. Avoid flash directly on the label - the glare usually obscures exactly the digits that matter.