So, I started experimenting with other controls.

They all had messages saying that wouldn't work unless a macro was active. When I clicked on the other sub-windows of the program, I didn't see any of the expected data. When I enabled the Serial I/O selection and started the ALDL stream, I saw text scrolling by in the data window. I started in the Live Data window (default).

I started with that and got *some* communication, but not all I wanted. Luckily, there is a file for 1993 s-series Saturns in the list. The version 4 Eval version has some included ALDL data stream configuration files that are car-specific. The early 1990s Saturns appear to use 8192 BAUD.ĮFLive version 4 Eval DID work with my 1994 SL2. Neither setting produced any communication with the car. WinALDL says it's for 160 BAUD ALDL and has 2 BAUD settings: 24. This afternoon I connected the ODB-to-USB cable between the car's ODB1 connector and USB port of my laptop, and tried a few of the free ODB reading programs available. One of the pages on their website said it was compatible with early 1990s Saturns. I ordered one of the GM ODB1 cables from here. I've got a 1994 Saturn SL2 and want to be able to read data out the ODB1 port. The ALDL interface circuit components soldered to board: Here is a picture the resistors, transistors, diode and DB9 connector: This circuit consisted of two transistors one connecting the 'ALDL data' to 'RS232 Receive', the other connects the 'RS232 Send' to 'ALDL Ground'. Since the first circuit performance wasn't great and the whole thing was messy, instead of refining the first circuit i thought i should try a new design. This circuit worked, but for some reason the response was slow, i couldn't make it work with a Usb-to-Serial converter, and on some PCs you can't take power from Pin4 so you have to connect it to 12v external power source (the resistor stays). The simplest ALDL interface circuit i could find consisted of one transistor and two 10k resistors it simply connected the data pin on the ALDL plug to the RxD(Receive Data) port on the RS232 on the PC through the transistor. Īldl has a port for sending data and the RS232 on PC has a receive data pin (RxD) so the easiest way is to connect them directly but since each system uses a different voltage we should put a transistor between them. I've always wanted to connect my laptop to my GMC van OBD1 based ECU, a little research on the internet lead me to a simple circuit that could make that happen.

Winaldl cable gm