Josh wrote:
>Well, yes, but see this web site:
> http://www.obdii.com/connector.html
That's a pretty good site. Thanks.
>Unfortunately, different manufacturers use different protocols.
Yes, but in OBD(I), there were different connectors, different
codes, different techniques, etc. for getting DTCs. Now there are
only 3, according to www.obdii.com.
And if you want to be really ugly, GM has theirs (SAE J1850 VPW),
Ford has theirs (SAE J1850 PWM), and everybody else uses a standard
ISO 9141. :)
I wrote:
>> Well, actually, pins 2, 4, 5, and 16 are standardized.
>> Pin 2 is the ECM/PCM data.
>> Pin 4 is chassis ground.
>> Pin 5 is signal ground to the ECM/PCM.
>> Pin 16 is battery power.
>>
>> With the wide part of the connector at the top, the pins are
>> numbered L-R 1-8 and the narrow part on the bottom is numbered
>> L-R 9-16.
>>
>> \ 1 2 3 4 5 6 7 8 /
>> \9 10 11 12 13 14 15 16/
I got this out of a GM book. This is standard for protocol SAE
J1850 VPW, but only GM uses this I believe. Sorry, my mistake.
My original statement was 1) they use a common connector and 2)
flash codes (where the MIL/malfunction indicator light flashes and
you have to count the number of flashes to determine the code) are
gone.
The earlier discussions about turning the ignition key on and off
for 3 or 5 times on a Neon only apply to OBD(I) technology. And as
far as getting codes and stuff for servicing your car, OBD-II is
not owner friendly. It's supposed to be a lame attempt to keep
individuals from tinkering with their own cars.
Also, OBD-II monitors the vehicle's emission levels and is supposed
to turn on the MIL if emission levels exceed 1.5 times the
allowable emissions. It should make emission inspections a matter
of connecting a scanner to your car and check for emission DTCs.
I/M 240 type stuff should be unnecessary because the ECM/PCM is
monitoring the vehicle while under "load" and real driving cycles,
but does anyone really believe the government would give up a form
of control they have over us?
Not me.
Mumbles
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