What the heck is my ECM doing???? - Page 2 - LS1LT1 Forum : LT1, LS1, Camaro, Firebird, Trans Am, Engine Tech Forums

indigorhages · 11-18-2012, 05:28 PM

Well it's good to know that I didn't accidentally screw it up by trying to scan it with an OBD2 scanner. I finally got Freescan to download it, I'll see what I come up with. Is anyone actually reviewing the .uni files I uploaded?

bobdec · 11-19-2012, 09:26 AM

First .uni is only 8 seconds, 3 seconds prior to start then start and 5 seconds of running in open loop. The 2nd .uni of 27 seconds starts when engine has been running and is in closed loop. In both logs everything looks OK there are no DTC's. I did see that you selected the transmission data window and in that display the A4 solenoid status bits are showing open circuit. That is normal since you have an M6. Those bits s/b ignored, as the circuits do not exist in an M6. The PCM knows that as there are no DTC's posted. It's only the red light DTC OK display on the main screen in Datamaster that is significant.

I did see your TPS voltage is 0.24 volts saying your TB blades are closed a little to much, at that same time your IAC is reading 50. Best to get TPS between .45 and .75 and then check that IAC is 40-60. Is your TB stock ? Having TBS at .24 and IAC at 50 sort of points towards OEM. If you open the stop screw to .45 volts, and the IAC goes higher than 60 let us know..

As far as the tranny, I can't help on that. I would suggest a new thread for that topic where it would get the attention it deserves. The only control PCM has for an M6 is skipshift that locks out 2 & 3, and that would be inactive w/key off. If no responses here then you could try Drivetrain - CamaroZ28.Com Message Board

indigorhages · 11-19-2012, 11:14 AM

*enlists car savvy friend to translate your findings to English* lol

but you're saying that you're not seeing any DTCs in my logs? When I looked at the DTCs for Engine and Transmission, each one had at least 30 code numbers that were highlighted green in both tests....was I misreading the software?

bobdec · 11-20-2012, 10:10 AM

If this is the screen you are referring to ? If so then Green is OK, Red is error and Gray is n/a . Only Red indicates a DTC failure.
A DTC is a Diagnostic Test Code, so a Green DTC XX in Datamaster indicates the PCM is testing for that XX condition. It is a DTC 'FAILURE' in Red that indicates the test failed. In your display the green says the PCM is testing the A4 solenoid circuits (green indication), but since you are an M6 the PCM ignores those circuit failures and does not post a Red DTC error condition.
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indigorhages · 11-20-2012, 10:22 AM

yup yup, that's what I'm referring to. Well, I feel kinda stupid right about now.

bobdec · 11-20-2012, 10:52 AM

These cars make us all feel that way at times... When I first got the Z28, the car missed for a couple of days and then died, I got it towed, and ended up paying a local 'old school' service shop $275.00 to replace my PCM, AND a HV wire from coil to OPTI. They had no test equipment or PCM experience and just swapped parts for two days till it ran. Looking back I'm sure the wire was the problem.. I vowed never again.. so I got a service manual and I started out to learn about ECM/PCM engine management systems. First a Hypertech module, after reading the forums I threw that away and went to mail order, then did a lot more reading and moved on to tuning on my own. It's taken a few years, and I'm still half in the dark when I look at all the PCM tuning on my wife's newer OBD2 setup. Unless you have the opportunity to hire on at a dealer/service setup that pays for training, we all start at the bottom and learn as we go. Good thing we have these forums to share knowledge, ain't many F-Body shops around these days.

indigorhages · 11-20-2012, 12:00 PM

well now that we've established the ECM is okay and stuff.... Is there a way for me to get a backup of the custom setup on that ECM? I'm still asking the former owner if he has such a backup

, but just in case....

95 Firehawk · 11-20-2012, 02:13 PM

Quote:

Originally Posted by indigorhages

well now that we've established the ECM is okay and stuff.... Is there a way for me to get a backup of the custom setup on that ECM? I'm still asking the former owner if he has such a backup

, but just in case....

Coco sums that up pretty well in post #2. I'd change the file type to "read only" so you don't accidentally mess up the original tune if you choose to mess around with it.

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indigorhages · 11-20-2012, 02:34 PM

will read post #2

bobdec, with the TB/TPS/IAC stuff you were talking about..I know the car has some sort of Lloyd Elliott package on it (attempting to weasel specifics on that out of former owner right now) and I believe I read on the company's site that their modifications affect some of this stuff. (http://elliottsportworks.com/) Knowing that, is the setup you saw something that I should look further into still?