I finally got everything I needed to gather data from my LO3 '91 Camaro, but I cant get it to work right. I have an old 486 thinkpad with winaldl installed and built the cable in the pic below. When I plugged it into my aldl connector and started the car up it idled up to about 1050 RPM like I read it would do, but the program wasnt reading anything. I have the ecm type set on 746 and I didnt touch any of the other settings. I heard that the cable could be too long. How long is too long? Any suggestions would be appreciated.

 

if you built the cable like above it means you are using the laptop as a power source... most laptops will not put out a power source to the serial port unless they are pluged in, i aint got no clue why they just wont do it off the battery... kinda sucks but try pluging in the laptop and see if it works...

 

The battery in my laptop is dead so the only way it works is to plug it in w/ the AC adapter.

 

I had nothing but troubles with my compaq laptop until I tried the other WinADLD wiring diagram that uses the 12 volt source. Now it works great.

 

have you got a pic or diagram of the wiring that you use?

 

I use the same interface with an 870 and it works fine powered off the laptop. If your rpm is going up at idle your A,B is correct but I thought ( don't know as I haven't worked on one) the later cars didn't use the E pin and used the M pin. I also seem to remember some saying the 1 transistor interface only works well at 160 baud.

 

My p75 thinkpad has a hard enough time with winaldl so I'm not sure if the 486 is up to par. Make sure you've got nothing else running when you open winaldl. The cable shouldn't be more than ~6' long. Any longer and you'll get frequent loss of data. My cable is made from computer power cord ac wire and it's 4' long, I drop a line every 250 packets or so, not a big deal. Also do you have the transistor and resistors up near the serial port or down at the aldl connector?
Thinkpads to require the power supply to get the 12 volt source at the serial port. Did you try changing the com ports?
Oh yeah, and most importantly, did you disable the built in modem and infa-red ports? If you didn't, that's your problem. I had the same problem. Both of those built in features use up the avail com ports so disable both of them. If you need to know how to do it let me know. Also for winaldl to even open I had to have internet explorer installed, don't ask me why cause I don't know.
I'd also remove the resistor from pins a and b, that isn't required for the 8746 to send data.

 

Well my cable is about 8 or 9' long and the transistor is near the com port. I tried changing ports and it would only sat com 1 was OK. My thinkpad does'nt have a built in modem. I installed a PCMCIA modem in one of the slots but I tried it with this removed and it still did'nt work. I did'nt see any infrared ports and my comp. does'nt have Int. Explorer on it . Any more suggestions.