OBDII Protocol

[jeff88]

So according to my Ultragauge I have the 9141 OBDII protocol. According to the UG user manual, this protocol essentially sucks (they use different words! ) It got me to thinking if a protocol change is possible. I'm not worried about cost or the nitty gritty, just if it is possible and a basic idea of what would be involved.

Thanks!

[Quezacotl]

You would need to replace the whole ECU, if you first find compatible, and adjust everything again.
Why it sucks?

[RobertISaar]

all OBD2 protocals suck, they have way too much overhead for rapid datalogging.

changing your protocal isn't something simple, since not only would you have to change the programming of anything in your vehicle that communicates with the PCM, you'll probably need to modify the internals of the PCM as well, neither of which are going to easy to do.

[Quezacotl]

MegaSquirt - Electronic Fuel Injection Computer by Bowling and Grippo ©2010
But not worth if all you want is to change the OBD protocol

[jeff88]

Originally Posted by Quezacotl

MegaSquirt - Electronic Fuel Injection Computer by Bowling and Grippo ©2010
But not worth if all you want is to change the OBD protocol

Except that in California, that is probably going to be illegal, unless it is a track car.

[toc]

Nothing wrong with the 9141 protocol.
It's fairly easy to understand...

Why would you need to change it? It's a very fit for purpose protocol...