If you a replacing an ECU on a car with a new one, you have to flash it with the right firmware for the vin number of the car. At least that's the case with Chrysler. My friend works at a Chrysler dealership as a tech, and he says that basically anything you now put in on the car, be it something complex, like the ECU, or something simple, like the windshield washer control module, it has to be programmed. If you don't program it, it doesn't work. On BMW M3 you even need a computer to "program" a new battery.

> On BMW M3 you even need a computer to "program" a new battery.

You're "calibrating" the battery. This has been around on BMWs for a long time (my 2008 535xi had this). If you replace the battery yourself and obviously can't program it in, the car will bitch endlessly, but it'll still work.

I bought a new (to me) motorcycle last week. It's a 2008 and it has loads of electronics (compared to my old bike). One of them is an immobiliser that deactivates when it detects a transponder inside the key.

The motorcycle comes with three keys: a red one and two black ones. The black ones will turn on the motorcycle but can't be copied. The red one can be copied and is intended as backup in case you lose the black ones. If you lose three the only way to turn the motorcycle on is to get a new ECU from the manufacturer.

I guess most modern cars are the same.

That sounds terrible. The absence of crap like that is one of the things I love about riding a motorcycle. Does the manufacturer of that motorcycle not realize that they are sacrificing one of their competitive advantages by importing that kind of complexity?

I think maybe I'm not going to sell my 1995 Nighthawk after all! Sounds like it might make more sense to just keep it running, simple and straightforward, without having to worry about all this fragile automation.

I think it's mostly to discourage theft.