"Yousuf Khan" > wrote in message
...
> Jeff Strickland wrote:
>>
>> "Yousuf Khan" > wrote in message
>> ...
>>> Scott Dorsey wrote:
>>>> The problem is that it will ONLY show you the engine codes. And that's
>>>> sometimes useful, but it's a tiny fraction of the amount of information
>>>> that is there.
>>>
>>>
>>> Are the formats of the non-engine-specific codes different? Will buying
>>> the round BMW plug and attaching it to a laptop be able to display those
>>> non-engine codes?
>>>
>>> Yousuf Khan
>>
>>
>> All of these codes should be available through the OBD II connector ...
>> http://autorepair.about.com/od/obdco..._1996_year.htm
>
> But Scott Dorsey said we won't see all of the possible codes coming out of
> the standard OBDII ports. You're saying we will. Which is right?
>
> Yousuf Khan
There is program data that the OBD II port will not see, Scott is 100%
correct there.
But if there is OBD II data, the OBD II data port will disclose it. That's
what OBD II is all about. The Check Engine Light (Malfunction Indicator
Light -- MIL -- is the technical term under the OBD II specification) will
come on if any of the codes in the table I gave you is stored. Let me
restate that, there are codes that might not turn on the MIL, but are in the
tables I gave you, the OBD II data port will show them. Any Code that lights
the MIL will be shown at the OBD II Data Port, some codes that are shown at
the data port might not turn on the MIL.
There can be vehicle data that is not OBD II data, and therefore will not be
shown via the OBD II data port. If you were into tweaking the program, you
might be interested in some of this other data. But, if all you wanted was
to figure out why the MIL was on, the data port will tell you why, and will
include the P1nnn codes. All '96 and later vehicles sold in the USA (and
other countries as far as I know, but don't really care much about) will
display the P0nnn codes. These codes are all common among all cars. If the
car has a system that generates a code, the same code will be generated by
all cars. These codes are P0nnn codes. Some cars will not produce a given P0
code because they do not monitor the system -- an example is the After-CAT
O2 Sensor, all cars that have this sensor give the same code, but some cars
do not have the sensor so they simply can not produce the code and nobody
cares.
The P1nnn codes (manufacturer specific, by definition) codes are for systems
that some makers employ. In theory, a BMW specific code would be for a
system that only BMW monitors. The theory breaks down a little bit relative
to these codes though. Example, P1246 and P1260 have different meanings
depending on the maker yet the conditions reported would reasonably be
problematic for all makers and therefore should be a P0nnn code.
Having said that, if you look up a code that appears on your BMW, and the
tables say FORD ONLY, or whatever, then that system described on the table
is not the one that is asking for your attention on your BMW. Or, the tables
are dated, and the code is newly added.
Since you have a PC based scan tool, you should have the latest code lists
available onboard the PC, or via an update that has not been downloaded.
Your PC should give a code along with the text of the problem, P0nnn -
FRAMIS VALVE MALFUNCTION. If the Framis Valve is monitored by a P1nnn code,
it should still be displayed on the OBD II data port.
The whole point of OBD II is that repair centers were fleecing consumers
under the OBD I system because they were charging lots of money to simply
pull the codes. The rationale they used was that the codes were some sort of
secret that required specialized training and unique and costly equipment.
To the extent that the automaker's schemes to get the codes was different
among different makers, and sometimes different among the same maker but
different models -- a Thunderbird might display its codes differently than
an F150, for example -- the repair shops had a valid claim to your money.
OBD II is a rule to standardize the means of extracting the data and
diagnose the data extracted. The whole idea was to allow people to
understand what was wrong with the car and do repairs themselves without
having to learn the technique to get the data and the meaning of the data
they got for all of the different vehicles they might own.
I own 5 cars. I have to learn several different ways to get the data, and
figure out what the data means, for each of them. OBD II makes it easier for
me to fix my cars, once I migrate my fleet to post '96 production.