I did alot of reading about connecting a laptop to the ECM in my car and finally decided to give it a try. I made a cable from ALDL connector to serial and connected it to my laptop, I don't want to buy one, since with S&H from the US to the netherlands brings the cable to over $100. I first tried the single transistor but with no lcuk, then i tried the cable with two transistors and separate 12vdc source, Tunerpro RT recognizes the cable, so i figure that is a start. Put the 10k resistor across pin A and B, my idle increases and runs richer, but when i try to connect nothing happens, i have tried several times, and let it try to connect for a couple minutes but still nothing.
Did find some odd things though, when shorting out pin A and B, my radiator fan turns on, but still get code 12 continuous flashing. Orange wire is pin E, which is data, 12v is present there. When turning on the ignition, my service engine light comes on, but does not blink once. After starting the engine, the light goes out.
I get the idea that the 1227165 ecm isnt exactly the easiest ecm to connect to, i hope that someone will be able to help me figure out what is going on.

 

Hi

I make the 12 pin ALDL to USB cable as http://reddevilriver.com/aldl.html

The 1227165 is a 160 Baud Pin E type ECM. That also means that the data only flows one way, and the data flow is started with the 10K resistor. Since the ECM is a very early attempt by GM, it has some flaws in it's design, one of them being that GM designed the ECM with it's operation being altered somewhat when the cable is connected. That is what you noticed with the 10K resistor connected.

Later OBD1 ECMs used a bi-directional data flow on pin M. TunerPro RT's test is to transmit a signal and then look for it to be reflected back into the computer. That will only occur with the electronics set up as the bi-directional mode. That is why you only saw the cable as testing 'found' with the two transistor circuit. That however doesn't mean your one transistor circuit was bad. It just won't test 'found' since it is a unidirectional circuit.

So why isn't your cable working? The biggest problem people have found is in using USB to RS232 adapters. Many of these adapters produce less than the standard of +12v and -12v. Some also have problems running at the non-standard speeds that GM used. Try using the cable using a direct RS232 port on your computer, assuming you are using the adapter. The direct RS232 ports on your computer are much more robust than the USB to RS232 adapters.

Also make sure you are using the correct .ADX file for your vehicle.

Try using these .ADX definitions

$6E 1989 Y & F CAR 5.0L & 5.7L
http://www.gearhead-efi.com/Fuel-Inj...4&d=1325460324

$32B 1987 - 88 Y & F CAR 5.0L / 5.7L TPI
https://dl.dropboxusercontent.com/u/...y%20%2432B.adx

 

You might want to take off your solicitation link

 

Thanks for the info, unfortunately it doens't help me very much. The cable i made is serial connection to my laptop, there is no usb to rs232 adaptor, and i have tried all three of those xdf files since i wasnt sure which one i have. Any other possiblilities that you can think of? Are there parameters in the laptop that I need to look at? I was using com1 when i was trying to connect.

 

sorry i meant adx files, not xdf

 

Well give me some ideas on how I should do this. I would like to give the OP an alternative to the cable he is trying to make if he can't get it working. I'm sure he would prefer buying the cable from someone who does know what he is talking about and knows about his specific application.

I also want to convey to the OP that I am knowledgeable in answering his specific question.

I also believe that if the link was to anyone else buy my own company that there wouldn't be any problem with the link right?

So is there a proper way to do this?

 

You will need to become a vendor to sell products and post your link.

The 165 can be a real bear to connect to. I live tuned a few weeks ago and went through trying 4 ecms until I had one that would connect.

 

You might want to try to download those .ADX files directly since I would think you had do at least on one of those convert a .ADS file to the .ADX file. TunerPro's .ADS import function does have some issues in converting the files.

Can you post a link to the one or two transistor circuit you are using?

I have successfully used the one transistor circuit on 160 baud ECMs in the past but I need to look up which exact circuit I used.

 

Tuned Performance - So would you rather I just mention the name of my company or is that a problem for the forum also?

 

ya, for both of those i needed convert from ads to adx with tunerpro. I will try them again with the links that you gave.

here is the wiring schematic that i used.[IMG]
https://www.google.nl/search?q=aldl+serial+cable&tbm=isch&tbo=u&source=univ&sa=X&ei=MmIGUt2CCMOVPMH1gZgD&ved=0CFYQsAQ&biw=1600&bih=799#facrc=_&imgdii=_&imgrc=K6H_JDsDLTbDsM%3A%3BFjKsdFw4lEFzPM%3Bhttp%253A%252F%252Fwbo2.com.au%252F~techedge.com.au%252F%252Fvehicle%252Fim%252F2tran.gif%3Bhttp%253A%252F%252Fwbo2.com.au%252F~techedge.com.au%252F%252Fvehicle%252Faldl160%252F160serial.htm%3B406%3B299[/IMG]

 

I opened up my old serial cable and checked - This is the circuit I have used successfully in the past.

Note to others - this cable ONLY works on 160 Baud Pin E ECMs.

 

thanks, i will try and find time this afternoon or tomorrow to make it and see if it works.

 

I don't care I was just informing you on the rules in case you were unaware.

 

ok, so i made a new cable and it connected on the first try, well, it says connected en then flashed data error and am still not getting any information on the computer. And the data error continues to flash every time after it says connected. And it was a different adx file, the one link for the %6E ecm is the one that connects.
I am now one step closer, but not home yet