Greetings! I am in the used OE parts business, and hear from time to time that many of the "brain boxes" of higher end vehicles are not re-programmable....I thought techs could use "flash" methods of programing a used computer module. Can anyone out there enlighten me please?

 

Most ECUs are no longer reprogrammable. Japanese and German vehicles always had encrypted ECUs, and apparently now US domestic manufacturers are also encrypting their ECUs because of emissions requirements.

 

You can't tune a 335i anymore?

That's completely dumb. People mod/reprogram after the car is bought. That should not affect the automakers CAFE since the vehicle was already purchased

 

Don't quite me on it, but I'm pretty sure tuners don't re-program the actual ECU in BMWs. There are tuner chips such as Dinan, etc - I'm not sure how they work, whether they are just "piggybacks" or they take control over the main ECU.

But in the case of Ford and GM, you could actually hook up a laptop to the ECU, and with the right software have the ECU completely reprogrammed. You could have your own fuel tables, you could bypass EGR, and so on. I'm pretty sure the newest GMs and Fords no longer allow you to do that.

In the case of Japanese and German car, you could never just reprogram the ECU, they were always encrypted. This is why extreme tuners opted for aftermarket ECUs such as AEM and others.

 

For current gen Mercedes, the ECU is reprogrammed directly (not through the OBDII port or piggybacked). Renntech, Weistec, and Eurocharged are all examples of reputable tuners that tune MB ECUs.

 

Ok makes sense. Thanks for the clarification

 

And welcome to CL and CAR CHAT as a brand-new poster.

Sure.....be glad to. Forget about chipping/re-programming unless the car is out of warranty. And, even if out of warranty, the car, to be legally registered, in areas where the EPA requires it, must pass a bi-annual emissions test.....which it may or may not do after reprogramming.

 

Actually, sometimes manufacturers do release new versions of firmware, that can flash rewrite the firmware on the ECU, but that firmware ships encrypted, and use wont be able to modify it.

 

Thank you!

 

Thank you!!