John.

""I'd already tested it, so if they couldn't repair it I would have preffered a call to let me know, rather than them testing a component they knew they couldn't fix.

I advised a refund would be acceptable to me & they refused.""

I agree and have said this again and again.

Every time you call them you get the flannel about this much to test it etc. I have always said "I dont need it tested" I have tested it and will attach fault codes and scope traces to show my findings - I need it Repaired and great if YOU test YOUR repair before sending it back.

I have not used an ECU testing repair service in years for that reason.

If it is a given, as it seems it is with any competent tecnician that the best test bench is the car itself then Lab ECU testing has to be wrong.
Or the other way round - I see no middle ground here.

Coming back to the belief that the best test bed for the ecu is the car itself, If you subscribe to that theory,then that makes a mockery of that industry because they do not put it on the car to test their repair. ?

As most Big Money Making enterprises these days, they are lucrative because they are wrong.

No better than most Engine Rebuilders - They dont Remanufacture or rebuild, they fix what they can see is broken using second hand or cheapest new parts and move on to the next one.