AGENT 86

I don't recall a wire in terminal "M" on the ALDL

Casethecorvetteman

This one i have here has none of them jumped, have you got enough spare pieces to give it a go Bill?

Looks like its almost the same apart from that...

Bill-35thAnvrsy-88

I totally agree and I'm convinced the serial port is good and working. Although the operating sytems are different, WIN200 and Xp access hardware (the serial port) the same way from what I understand.

Thanks Case!

Casethecorvetteman

Shouldnt be a concern, but i remember StingrayNut telling me about this and his 88 in an email a long time ago, did know what OS he was using there on the laptop though. At least we can be sure that isnt the issue!! (hopefully!!)

Bill-35thAnvrsy-88

I sure do Case. However, it appears there is some jumpering on the RS-232 on pins 2,3 5 and 9 and oddly none on pin 4 as I previously mentioned. In either case, I must jumper ALDL pins E and M together for my 88 and I don't see where your schematic is providing that either.


Thanks!
Bill

Bill-35thAnvrsy-88

Hmm, I think I read your schematic wrong. Maybe RS-232 pins 2,3,5 and 9 are not jumpered and it means to use pin 2 of 9, 3 of 9 and 5 of 9.

Hmmmm.

Bill

Casethecorvetteman

Those numbers down the far right of that one is which pin on the connector, as in pin number 2 of 9 pins OR pin 3 of 25 pins for RxD depending on which connector you wish to use.

Bill-35thAnvrsy-88

Case...Your schematic is electrically the same as the one I'm using from Agent86 it seems. Just drawn differently.

What do you think?

Casethecorvetteman

thats it mate
It looks that way yeah, it just has no jumpering on any connections at all. Id be interested to see if it works this way or not....

Bill-35thAnvrsy-88

Yeah but I'm currently NOT jumpering anything and...it doesn't work. My issue (and I can pretty much gaurantee) is the E/M jumpering clearly stated by Datamaster. I don't think you will have this issue. Don't you have a '94?

Casethecorvetteman

I do indeed mate yes. Used to have an 87, and from memory, i dont remember there being any contact in the M hole on the connector either...
But according to this,

there should be.... But only if it has 8192BAUD....
And also looking at this site, it shows there is too....
http://www.techedge.com.au/vehicle/aldl8192/8192hw.htm

Bill-35thAnvrsy-88

Case...I agree and I've provided a pic of my connector. I was thinking maybe I was looking at this backwards but to pull codes, I jumper pins A/B and it works fine so that would place pin M right under pin A on the bottom right. Correct?



As you can clearly see, there is no pin in the M hole...it's empty!

What kinda car I got here anyway...a kit car?

I'd sure like to see another 88 connector!



Thanks!
Bill

Casethecorvetteman

Thats afirmative Bill, bottom left pin is G which is fuel pump, F ubove it (top left) is torque converter clutch. That is exactly as i remember the connector. Are you confused too???

Bill-35thAnvrsy-88

What I am confused about is why I don't have a terminal in Pin M !! I feel I can't go further until someone can clarify my Pin M situation! Does your 94 have a Pin M?

AGENT 86

"M" is the data line in later vettes. The reason i see them jumping "E" and "M" is it covers there *** on getting data from whatever year. There is probably nothing in the "E" terminal on later vettes.

Bill-35thAnvrsy-88

Well then...if that is so, off I go to different troubleshooting I guess!

Thanks!
Bill

Topless87

That pinout above is wrong for your vette. Pin M does nothing, and pin B is not optional if you want either data stream.

There is no PIN M.
A=ground
B=Diag Mode
E=Data

Pin E will talk in both 160 AND 8192 mode. That is why you need the 2 transistors to tell the ECM to go into 8192 mode if you want. Otherwise it will just spit out 160 baud data when you connect A/B with a 10K resistor. FYI: the difference between the two streams is not just speed, but also there is more data in the 8192 stream.

If you only interested in the shorter 160 baud data stream, why not use WinALDL. Its free, and I have found it to be less fussy when it comes to home made interfaces.

(ALSO, if anyone is interested, in between each 160 baud packet, there is a 1/10 of a second window where the ECM will "listen" for a command. There are only 2 commands; 1> clear codes, 2> go to 8192 mode)

Bill-35thAnvrsy-88

I deifnitely want the 8192 stream and I'm using the 2 resistors but I'm getting a No PCM Sync in Datamaster. I think it's a timing issue and I will tweak the ALDL timers in datamaster and see how that goes.

Woops...you said "transistors" so, I'll attach these and see how it goes!

Thanks...that's good info Topless87 and things are getting clearer!

Bill

Topless87

I suggest testing 160 baud stream first, its simple, and its always on and you can go to the more complex one after you have that one working.

One thing is when in diag mode, you fan should come on and you should be at about 1K RPM idle. Is you fan running? If not, you are probably not even diag mode.

(correct me if I'm wrong on this one, but my 85 and 87 both do this)

Casethecorvetteman

Different connector under the dash on mine to yours, they are numbered 1-16.
Yep. That is correct about fan. Not sure on idle speed changing....