Not that that stops the manufacturers from charging ridiculous amounts
of money for ECUs.
Likewise the prices garages charge(d) for diagnosis on their computer
diagnosis machines.
I had an intermittant fault on a Rover years ago, They wanted to charge
60 quid / hour
with the car on "soak test" until the fault appeared.
They would have happily charged me about 1000 quid for the process !
Simon.