From: vlasis@cybernet.cse.fau.edu (vlasis theodore)
Newsgroups: rec.autos.tech
Subject: Re: Diacom ECM Software Review
Date: 9 Jan 93 19:19:30 GMT
Organization: Cybernet BBS, Boca Raton, Florida

Michel_Denber.WBST147@xerox.com writes:

> Micro-review: It's awesome.
> 
> Mainframe review: Since I was such a good boy last year, Santa brought me a
> copy of Diacom for Christmas.  As fate would have it, my car started doing an
> intermittent stalling number just three days later, so I got a chance to try 
> out in actual combat.  If you came in late, Diacom is a software package that
> connects your IBM PC to your car's computer and gives you a realtime display 
> all of the sensors as well as various internal ECM parameters.  There are
> versions for GM and Chrysler.  I got the GM version.  The package includes bo
> 3.5" and 5 1/4" disks, a comprehesive manual, and adaptor cables.  One end
> hooks up to your PC's parallel port, the other goes in the car's diagnostic
> connector (ALDL connector).  The program will work on any PC or compatible wi
> 512K RAM.  However, the manual states that it will not work with Sharp 4500
> series machines, Tandy desktops, or the Tandy 1400 laptop.  I used a Toshiba
> T2200SX and it worked fine.
> 
> Using Diacom is easy.  You can run it right off the floppy or transfer it to 
> hard disk with the supplied install utility.  You plug in the cable, run
> diacom, and type in your car's VIN.  The screen now shows all of the paramete
> the ECM will display.  Then you plug into the ALDL connector, turn the igniti
> key on, and give the "link" command.  When the system links up, the display
> activates.  The update rate depends on the particular ECM.  In my 88 Celebrit
> with the "high speed" P4 ECM, I got 10 updates/sec.  My wife's 84 Buick with
> the older C3 ECM gives 1 update/sec.  On the Chevy, I get readouts of 42
> different parameters, from basic things like RPM, battery voltage, and coolan
> temperature, to sensor values including MAP, EGR, and O2, to data unobtainabl
> any other way, such as ECM integrator counts, block learn multiplier counts,
> and block learn cell number.
> 
> So what good is all this?  Well, my Chevy started this thing of stalling at
> idle.  The check engine light never came on and no codes were set.  So what's
> wrong with the damn thing?  Could be anything, right?  The shop manual has ha
> a page of things to check.  I plugged in Diacom and found the problem in 30
> seconds.  Literally.  In less than one minute I had it figured out.  Diacom
> showed me that all of the obvious culprits, like TPS or EGR were fine.  What
> wasn't fine was the oxygen sensor voltage.  It would periodically drop to 0.
> Half a second later, the car would stall.  Happened every time.  It couldn't
> have been more obvious if the O2 sensor had jumped out and hit me on the head
> Most of the time, the voltage was OK.  It was fine while driving around.  But
> as soon as the throttle went to 0%, the O2 output would become erratic.  When
> it went to zero and stayed there, the car stalled.  I replaced the sensor and
> it's been fine ever since.
> 
> Needless to say, I'm sold.  Diacom costs $300.  I figure I've already saved
> around half that just in this one repair, either compared to taking it in to 
> shop (not to mention the mental anguish of having Mr. Badwrench monkeying wit
> my car) or in terms of the time it saved me.  Since the oxygen sensor isn't
> even listed as one of the possibilities under "stalling" in the shop manual, 
> figure it would have taken me from 4 to 10 hours of grubby, painstaking
> detective work before finding the real problem.  Add in that the O2 sensor
> isn't the easiest one to test.
> 
> Diacom will also accumulate data over time, from 20 seconds to 20 minutes
> depending on the ECM.  It will then dump this in a file compatible with DBase
> or Paradox.  I read my data into Paradox and made a nifty graph showing O2
> voltage vs. time.  Diacom is like someone handing you an aircraft searchlight
> after you've been trying to find your way in the dark by striking matches.
> Take the age-old question, "are my fuel injectors plugged"?  Diacom shows you
> the fuel injector pulse width in milliseconds.  If your injectors are gummed
> up, this number will go up as the ECM holds them open longer to compensate.
> Diacom also gives you a direct readout of any stored trouble codes and lets y
> reset the ECM from the keyboard (on some ECM's).  You can command the ECM int
> ALDL mode, field service mode, normal mode, or system-backup (limp home) mode
> I can't imagine how I ever got along without Diacom.  Break your piggy bank,
> rob a bank, sell your kids, do whatever it takes, but go get a copy of this -
> it's that good.
> 
> Downside: although the disk isn't copy protected, it uses a dongle.  Normally
> I am morally opposed to buying programs that use dongles, but at least this o
> isn't totally obnoxious, since it's part of the cable you have to plug into t
> parallel port anyway.  There's a customer support number (not toll-free
> though).  I called them once, before I bought it actually, to verify that is
> would support my speed-density converted "V6 from Hell" and found the people 
> the other end to be friendly and technically knowledgeable.
> 
> Disclaimer: I have no connection with Rinda Technologies whatsoever, other th
> as a (very) satisfied customer.  Happy troubleshooting!
> 
> 			- Michel
> 
> denber.wbst147@xerox.com




does anybody know of similar programs for Japanese or European cars ?

Thanks 
Vlasis
Newsgroups: rec.autos.tech