Our Community is 940,000 Strong. Join Us.


OBD 1 code format for 94 Lesabre v6 3.8L


jerryls
10-05-2006, 03:22 PM
I have determined I have on OBD1 computer with a 16 pin OBD 2 connector on my 94 Lesabre. There have been many posts on this and I know this car will not read out codes by blinking lights through shorting any pins. I took the car to a dealer and asked what it would cost for them just to read the code and they said $95.00! I refuse to pay that for a few minutes of work!
Does anybody know where I can find out details on the serial stream of data that comes out of pin 9 the serial port?
It's ironic that it will probably take me many hours of time to interface my laptop and read the codes, but it's the principle of not being ripped off.
Thanks

maxwedge
10-05-2006, 03:38 PM
95 dollars, yes, and a 3,500 dollar scanner must be considered here. Indpendent garages charge less and most have a scanner that will work on those transitional years.

Bassasasin
10-05-2006, 09:20 PM
So you want the protocol language of the codes.. The handshake signal, Baudrate and decode of the pulses. That is which the little cheap scanners already know and do.

Your on a quest.
The 730 ECM communicates on a single serial TTL line with 8192 bps, so you need a small circuit like this to interface between the TTL signal emitted by the ECM and the notebook´s RS-232 COM interface (9pin connector pin# shown). Drawback: It needs a +12V supply, wich can be obtained from the cigarette lighter socket.

http://pweb.de.uu.net/pr-meyer.h/aldlintfmax.gif
http://pweb.de.uu.net/pr-meyer.h/aldl.htm#aldlmon

http://www.techedge.com.au/vehicle/aldl8192/8192hw.htm
http://www.oica.net/htdocs/WWH/OBD/GTR/Module%20B.pdf#search=%22decoding%20obd%20signals% 22
http://www.geocities.com/MotorCity/Shop/1624/95cam2.html

jerryls
10-07-2006, 10:32 AM
Hey Thanks alot- this is great information. I will easily be able to capture in the data to my PC, since I do electronics circuits as a profession. What I need to know is what the car is transmitting. Is that what those free programs interpret? All I really want is to read is the trouble codes. I see the serial data constantly coming out of the serial line when I turn the ignition switch to on. I wonder if this data is the error code, or some other data being sent out. I have an OBD 2 reader that of course gives an error because the pinout is different, but if I translate it to the correct pins via a cable, I wonder whether that would read out the codes?

Add your comment to this topic!