DA Data Errors?

**delcowizzid** · 08-18-2013

try $12p in it and see if it logs will clear any doubt of the ecu it has pretty solid comms.if the issue is still there ide be looking at an earth wire going high resistance when hot or something

**EagleMark** · 08-18-2013

Yeah but this is normal behavior for so many I've only read about, never had my hands on one.

But I do wonder and Robert may know... is this more prevalent to Corvettes then camaros or? What I'm thinking is fiberglass body and noise? GM went through a lot of trouble to cover distributor and ignition wires back then...

**RobertISaar** · 08-18-2013

i think i've seen it equally in both.... but it has been a while since i've looked into it.

i would think if it were that, then the 7727 equipped corvettes from 90-91(and the ZR1 as well) would have the same problem, since those are also underhood(and i assume in a similar location). those.... it's just dataline chatter that trips up datalogging.

**xtreamvette69** · 08-18-2013

delcowizzid...never heard of a $12p but i will look and try one if i can to see if that helps.
and yes i was thinking ground issue once hot too thats why i cleaned all the frame,engine,and ecm grounds and added extra(might still add more idk yet.

EagleMark.. yes i have seen a few stories about the 165's as well but there are equil or more stories that people have no pproblems which leads me to belive this is a fixable problem just that nobody has bothered looking into thouroghly yet...yet!!
tbh i would think the thick fiberglass would help insulate and isolate against electrical noise moreso then a steel body but i guess depends what type of electrical noise your trying to shield against.

RobertIsaar....it is true that the later corvettes you speak of have the ecm underhood but the early portion of the c4 corvetts 84-89 all had the ecm inside the car located under the dash.

i do however belive that it could be associated with some sort of engine noise though because i think it errors faster when revving etc rather then just idle, but i will have to further test that because it may be that it just heats things up faster.
another test i'm planning will be to remove the ecm case again and add thermal past to the contact areas of heatsinks to case as well as add fan cooling for testing purposes.. i will get to the bottom of this or hopefully at least get an answer as to why... just seems odd that in shop enviroments i have never had troubles or heard of troubles having shop scanners (handhelds and oem scanners) hook to and communicate with any.. and before you ask if handheld can connect when TP cant, the answer is nope, although my handheld is far from oem gm scanner equipment or pro.

but any and all possibilities, ideas and things to test are welcome to try and help me solve this as i dont really want to have to liquidate all my equipment to buy a megasquirt as i wanted to wait and buy one of those after some experiance for my HSR stroker.

oh and i forget to mention another test i did When TP lost connection and wouldnt connect besides trying the handheld, i also tried to jump A&B terminals ALDL and that was working perfectly..fan came on and started flashing the all ok code 12. dont know if that means anything but just more info..

at all times when checked tunerpro says the cable is found and functional.. when unhooked from vehicle of course.

**xtreamvette69** · 08-18-2013

oh also....is there a reason that my cable when switched to the 10k position doesnt change the way the car runs(idle or anything) switching between open and 10k makes no differance. i do switch it to 10k to hook up then sometimes switch it to open and other times i dont bother and just leave it in the 10k mode and everything is the same.

i was under the impression that the 165 would be like the 870 in the respect that when in 10k car would run differantly?

anyone familier with the 165 and the 10k vs open position to verify this?

**RobertISaar** · 08-18-2013

with the 7165 and any other P4 unit that needs a 10K to start a connection(i don't think there are many), those generally don't add spark and modify idle speed when in ALDL mode. it's the C3s that you have to watch out for.

**Six_Shooter** · 08-18-2013

Originally Posted by EagleMark

Yeah but this is normal behavior for so many I've only read about, never had my hands on one.

But I do wonder and Robert may know... is this more prevalent to Corvettes then camaros or? What I'm thinking is fiberglass body and noise? GM went through a lot of trouble to cover distributor and ignition wires back then...

The issue is that the only code that most of us are familiar with, that is used in the '7165, are $32, $32B and $6E. It could very well be possible that the code itself has connectivity issues.

As an example, I use the '7730/'7749 and have used different codes in them. Looking at my car directly. I have used $59 for years, without issue, quick connectivity and quite solid. There are a few data errors every now and then, but very few. I recently swapped to $58 for some testing and found that at times it takes longer to connect, and data errors are far more frequent. There is a patch that is said to get rid of this (and allow use of an AutoProm), that I haven't tried on my car yet, but have on another car it worked the way it was described. so that points to a code issue.

I will be testing $12P soon, since I am mostly done with the adapter harness.

**xtreamvette69** · 08-19-2013

all good info and true but i know there is a cause and with having a cause means there has to be a fix..maybe not a practical fix but a fix non the less lol

now onto my updates:
i have tried the following..
---lappy plugged in (not on batt power)
---cooling fan on ecm and chip keeping it all at 80*
---added battery charger onto the car
--- also worth noting was that the car disconnected from error at about the same time and same engine operating temp as before still, so seems that parts still pretty consistant at least in my case.
all these still = the same end result of the errors and ending of connection
now i did test the key off process before and it didnt work to restore connection but figured i would be more systematic this time.
this time i stopped connection on TP, unplugged from ALDL, shut key off, waited at least 20-30 seconds, turned key on, started TP to connecting, then plugged into the ALDL and connection success consistantly all 4 times that i had the disconnect.

that is all the testing i have done today but will do more later...

keep the ideas and possibilities coming, i will get around to testing them all soon as possible.. thanks guys.

**EagleMark** · 08-19-2013

Seems strange that when vehicle is at operating temp it has errors and dies... but you seem to have tested this to a conclusion.

Wonder what would happen if you waited till full operating temp and connected?

What is the ALDL.ds file this $6E uses? I remember one... not sure if this is it... that has 2 data baud rates. one is 160 and the other 8192. The ALDL.ds file would show if I am recalling this correctly and maybe it changes at full temp?

**RobertISaar** · 08-19-2013

IIRC:

32 is 160 only
32B is 160 and 8192
6E is 160 and 8192

**xtreamvette69** · 08-19-2013

Originally Posted by EagleMark

Seems strange that when vehicle is at operating temp it has errors and dies oh it no longer dies, thats all fine now, TP just loses connection at that point... but you seem to have tested this to a conclusion.

Wonder what would happen if you waited till full operating temp and connected? hmm interesting, i'm betting same thing as when i shut it off to reconnect but idk might be good test

What is the ALDL.ds file this $6E uses? I remember one... not sure if this is it... that has 2 data baud rates. one is 160 and the other 8192. The ALDL.ds file would show if I am recalling this correctly and maybe it changes at full temp?hmm i am not aware of what ALDL.ds file it is or what that even is but i have heard that some if not all use the 160 till it gets signal from scanner/software then goes to 8192 mode

i will tell you more if i understood what your asking, sorry <=== noob at keyboard lol

Originally Posted by RobertISaar

IIRC:

32 is 160 only
32B is 160 and 8192
6E is 160 and 8192

or that mhmm

**Six_Shooter** · 08-19-2013

Well, I have $12P running on my bench, connects without issue.

**EagleMark** · 08-19-2013

ALDL.ds files were what GM gave to scanner companies to make scan tools. This is what is used (easy way) to make the TunerPro .adx files.

Pretty sure this is correct for your system. Just open with Notepad.

**RobertISaar** · 08-19-2013

Originally Posted by Six_Shooter

Well, I have $12P running on my bench, connects without issue.

perhaps warm the 7165 up to the temps xtreamvette69 reported and see if it will get all kinds of flakey?

they seemed like reasonable temperatures for an underhood ECM at least. being mounted in-cabin probably helps keep heat out of it too.