OBD-II

[David Cooley]

On Tue, 13 Dec 1994, Craig Pugsley wrote:

> > | FYI:
> > | 
> > | OBD-II = On-Board Diagnostics II
> > | 
> > | (a system intended to indentify component and systems failures
> > | which prevent a vehicle from meeting emissions regulations)
> > | 
> > | Anthony Tsakiris
> > | 
> > 
> > 
> > It's more than that, it also defines a standard one or two wire serial bus 
> > that the ECM uses to communicate with sensors and other equipment (including 
> > diagnostic equipment), and a standard for the information packets that are 
> > placed on the bus.  So one diagnostic computer will work for all cars.  This 
> > would indeed be a good feature to include on a diy-efi computer.
> 
> Is the 2 wire serial bus structure the same as the CAN bus developed by
> Bosch as a comms system for motor vehicles? Motorola have (according to
> the article) a 68HC705X4 with a CAN interface. Also according to the
> article it is different to the J1850 bus.
> 
> Craig.
> 
> 


   Craig,
It is very similar to the CAN bus, and the ISO9141-2 interface is one of 
the allowed 3 ways of communications for J1850.
Dave