[Shop-talk] OBD/can/whatever scan issue.

[ElanS4]

Randall wrote:

>> Fairly new cars use the "CAN" protocol, and older scanners might not 
>> support it.
>> But the CAN protocol has been common for at least 7 years.
>
> Actually required by law in the US, since 1996 model year

ODB-II has been required since 1996, and is still required.  Even if your
car uses a CANbus internally, It is still required to output ODB-II codes.

CAN capable scanners can do more and access more data from the system, but
just to read error codes an old ODB-II reader will work fine.

>
> For example, my 95 Buick uses a CAN bus, but practically none of the
scanners support it because it is still 
> OBD-I and uses different (GM proprietary) addresses and message types than
specified in OBD-II.
This is a good example - CAN internally, bit ODB (unfortunately not II)
externally.

>
>My understanding is that OBD-II was supplanted in 2008 with a newer
protocol, called ISO 15765-4.  But I've not had to dig into it yet.


Again, there can be newer protocols used internally, and even piped
externally, but they also have to provide plain ODB-II.



Oh yea, all the ODB-II is required to read out is the mode status, and the
error code.  Many have been updated to included name and even more
information along with the code, but only the code number is required.
An example of this is my code reader I have to use on my Elise (ODB-II to
the outside world, CANbus internally).  The reader's data files do not
include Lotus - so all I get is the code (which I then look up in the
manual).  Plug it into another car and it me the code number, and
description of the error.

All you really need is the error code and the book to look them up.


Tim Mullen