View Full Version : Can't get my 1990 Lumina to talk to EFILive V4

July 26th, 2008, 07:19 PM
I have a 1990 Lumina with a 3.1L V6 and a 1227727 ECM in it, and I'm trying to make my first foray into EFI and data logging - without much success so far. I'm using the EFILive V4 Eval download right now - the UI seems great, but I just can't get it to make any sense out of the data stream from my car. Assuming I can coax this into working, the Pro version looks like exactly what I need, so any help getting it working would be greatly appreciated. :)

My laptop is running Vista x64 and only has USB ports (no COM ports), so I have to deal with a USB to serial converter. In the interests of keeping it simple and hopefully a bit more idiot proof, I picked up an OBD1 ALDL to OSB cable from http://www.aldlcable.com/sc/details.asp?item=aldlobd1u and tried it out - but it's not quite working right. The cable seems to be fine and I have a COM3 on my machine. I got a copy of HyperTerminal and watched the output from the serial port in there - it was getting something, and it displayed mostly as a bunch of funky high-ASCII characters. If I turned the key on, it starts spewing data. If I turn the key off, it stops spewing data. If I start the car, I get data spewed at me faster. The docs that came with the cable seem to indicate this means it's working right, and if I'm understanding the general format of the data coming back from the ECM right, this seems plausibly correct/expected. I work in the computer software industry so I speak geek, but this hardware/embedded stuff is new to me...

The ECM should be communicating at 8196 baud, and the serial port is set up what looks to be correctly. I get some green lines in the EFILive output when I try to do various things and when I click the "Detect Chatter" button, it usually reports back that the interface is fine and that it detects chatter - but not always. Is this due to some mis-configuration or something that's "not quite right' in the timing settings in the EFILive? :confused:

I've tried using a couple of different vehicle config files so far with no luck. The BAUH.xml config seemed promising, as did the CORVETTE_CAMARO_90_91.xml, but no luck either way. I was going to try out the 1990Z24.xml and GM727.xml files tomorrow to see if I had any better luck. Are the configurations specific to the ECM or does the PROM/MEMCAL affect things? As far as I understand it, the physcial 1227727 ECM is the same between my 1990 Lumina and a 1990 Corvette - only the MEMCAL and PROM differ so that the ESC, limp home, and PROM data are different. Right? I wouldn't think that affects the data stream radically enough to make it not work at all...


July 27th, 2008, 10:42 AM
Mike, welcome to the forum... :cheers:

I pm'd tech support.

July 27th, 2008, 11:20 AM
The first thing you need to figure out is:
Does your USB-Serial converter support 8228 baud rate. That is the baud rate that the EFILive software uses. It is the closest baud rate to 8192 (the ECM's baud rate) to which a typical PC UART can be programmed. It is within the % error tolerance of a standard PC UART chip.

EFILive assumes a UART is available to be programmed, many USB-serial converters have USB drivers that create virtual COM ports and the virtual COM ports do not fully emulate a UART. They only support the "standard" baud rates of 9600, 19200, etc.

If the baud rates are not close enough, then you will get junk data.

However, I am interested that you said you got some green replies back. That indicates valid data which should be impossible if the baud rates do not match.

Can you switch on the menu option: View->Serial I/O, then detect chatter for about 5 seconds then copy the entire text display (right click and "Copy All") and post in this thread?

I'd like to see the actual data. You may have a USB-serial converter that has a chance of working at 8228 baud.


July 29th, 2008, 11:15 AM
No idea on your problem man, but you're from my neck of the woods lol. Seattle born and raised here, spending the summer in Coeur d'Alene, ID then back to school in Spokane.

I bet you speak geek really well lol, a tiny little tech company has its headquarters in Redmond, WA.:secret:

Anywho:welcome: and hope we get ya figured out! If it was a V7 question Id meet you somewhere in Seattle and help out but I know absolute nothing about V4.