Beloved Leader <
Kim_J...@volcanomail.com> wrote:
> First of all, is this the right forum? If there's an automotive
> electronics forum, then I apologize for this post, and I'll ask over
> there.
news:rec.autos.tech , but I haven't checked it in quite a while, so I
don't know if it's any good. There might be a Saturn forum on a web
site or something.
> I would only use this once or twice a year. Right now, I go to the
> AutoZone, where they come out and run the scan with some Actron
> scanner for free.
You might ask if they will rent a scanner like they rent other tools -
basically you put the purchase price down as a deposit, take it home
for a day or two, and then return it in the same condition as you got it
for a 100% refund. (Some other auto parts stores do this too.) Even if
you buy a scanner outright later, this might let you play with a couple
of different ones before you do.
> I have laptops and desktops that run on Win XP and up.
For retrieving and clearing codes, I have always run my scanners with
Windows, either 98, 2000, or XP. I've never tried running one on any
flavor of Mac, or on a phone.
> I have a 1989 Oldsmobile Custom Cruiser. It has OBD I, so it might not
> be possible to get software that works with that, at least not easily.
I think a GM of that vintage will still have the "jump two pins in the
ALDL connector to blink the Check Engine light" interface, and the scan
tools of the day didn't give you a bunch more information than the light
codes did, but I could be wrong. An alternative would be to prowl Ebay,
Craigslist, etc for the original GM scan tool for it. I *think* the GM
tool was/is named a "Tech 2", or possibly some other number than 2.
> My mom's car is a 2000 Saturn wagon, and it runs on OBD II.
> What software or scanner do you have?
I have a couple of older RS-232 products from
http://www.obdscan.net/ .
The first one (bought around 2001 or 2002) came as a kit and had some of
the thinnest traces I've ever seen on a PC board, but it did work when I
soldered it together. It was able to successfully talk to my '01
Toyota, as well as a '96 Suzuki. It could only speak the protocol that
Japanese cars of that era used (ISO-9141, I *think*) so it couldn't talk
to American vehicles of similar vintages.
After three or four years, that one died, and I bought the then-current
version from the same vendor. It came assembled and could speak all
three of the then-current protocols. It could talk to the same two cars
as above, plus I'm pretty sure I used it on an early-00's Chevy and it
worked as well. It could not talk to an '05 Chevy that used CAN, the
latest protocol. I still use this one once or twice a year.
I can't remember which one it was, but the RS-232-side protocol was
documented for one of these. I wrote my own software (under DOS (!)) to
read a few values and after a little experimentation I got it to work.
The provided software, at least for the ones I have, is a Visual Basic
extravaganza. It can read data, read trouble codes, and clear trouble
codes, but don't push it harder than that. I have no experience with
the software they ship with newer tools.
I had trouble with a download from the Web site once, so I emailed the
company and got a prompt reply with working zip file attached. (As far
as I can tell, it's a one-man band.)
> What do you wish you had bought instead?
Sometimes I think it would be nice to have a self-contained tool, rather
than one that plugs into a PC/laptop... if a laptop is not available,
sometimes it is challenging to get a desktop PC close enough to the car.
I don't really use it enough for that to be an issue, though.
> What would you buy for your next device or software?
I'd talk to the independent mechanic that I take my Toyota to and see
what he uses, if it's not the Toyota dealership tool. I'd also check
with some enthusiast forums to see what they like.
Make sure to get one that speaks all the protocols. From '95 until
about '04 or so, I think there were three (ISO-9141, VPW, PWM), and
then in about '04 or '05, CAN was added.
One thing that I don't know the complete details on: All scan tools
should be able to read the mandatory [0] powertrain trouble codes. But
in an effort to lock out home mechanics^W^W^W^Wprovide better diagnostic
info, some manufacturers have sub-codes of the mandatory codes, and
either 1) only the manufacturer's scan tool can read the sub-codes, or
2) anybody can read the sub-codes but the meanings of the sub-codes may
or may not be documented in the service manual. (There are/were
lawsuits against the automakers to compel them to release *all* their
data.)
Also, as far as I know, it isn't often possible to re-flash or otherwise
tweak your ECM with a "generic" OBD-II scan tool. Even though at least
one of the standards specifies a way to authenticate to the ECM, I
suspect many manufacturers do their own thing in this department.
As a random note, there is +12 V power on the OBD-II connector, and the
standard says it has to supply at least 4 A. So you can hang a fair
amount of stuff off of it if you want to. (I can't remember if the
connector has +12 V even if the vehicle is +24 V.)
Matt Roberds
[0] in the US, anyway