An elecrical engineer was kind enough to build me an ALDL cable, but I am having some trouble getting it to work. When I plug everything in I get some data, but not enough that Craig's software, or others for that matter, go into diagnostic mode. Attached is a screen shot of the problem. Obviously it is working somewhat because some data is being received but not all of it...Has anyone seen anything like this?

 

Are you SURE the cable was built properly? I am just going by the message it is showing.

It looks to me like you are running Craig's software in "background" mode in Windows XP. I don't know if Craig has modified his software yet, but I was under the impression it had to work in "pure MS-DOS" mode.

I would do some searches on Craig's software to see if it will work in "background". Most of the DOS based software that utilize the COM Port need "exclusive use" and must run in MS-DOS mode only. I don't personally use Craig's software but the scan tool I use (Diacom) MUST run in MS-DOS mode for the port to work properly.

 

I am not sure the cable is 100%, that's what I am trying to determine. But i get the same results from WinALDL, CarBytes and ALDLMon. All of them see intermittent info!

I am waiting for my friend to answer me back, but I was wondering if anyone else has seen anything similar.

There is some data being read, but not enough it seems!

 

What computer/operating system?

 

Windows XP Pro on a Dell CPxJ PIII750.

I will be trying a P166 Toshiba this afternoon.

I will also shorten all the cables, my engineer friend think there might be too much noise on the lines.

 

Make sure the Toshiba runs W95 or 98 or 2000 and you can run in "pure MS-DOS" mode.

FYI, I have an extenstion on my cable to my ALDL and it is probably 25 feet long from the ALDL to the port. I use Diacom, but it too is a MS-DOS based program and will not run in a "background window" at all. It is one of the reasons I have not been quite so quick to put my old Compaq Laptop out to pasture.

 

The Toshiba will run the software fine and it will run it in a DOS box (this is how I run it on my Toshiba) using win 95/98.

 

same results with the Toshiba...

Here are some screen shots from FreeScan and CarBytes:

 

carbytes....

 

now my friend said I shouldn't need a 10k resistor to enable diagnostic mode, but just for fun tomorrow I will by one and try it anyway!

 

If you are using a 165 ECM you do need the 10k ohm resistor. Also if your laptop is beng used for the 12 volts for the cable it will run into problems as the battery comes off of 100% charge.

 

Actually the power is coming from the cig lighter and so is the ground. Why do I need the 10k resistor? I want to explain this to him.

I am no electrical engineer, but he is a very experienced one. He really seems to think that I don't need 1. I have sent him all the links I can find explaining how to build this cable. He has gone through all that and designed this particular board.

I just want to help him help me troubleshoot this!!!

 

You need the 10k resistor to put the ECM into the ALDL mode, making it transmit data to the serial pin on the connector.

 

OK i put a 10K resistor....nada!

Do I need to ground the cable on the ALDL plug?

Right now I am grounding from the cig lighter along with my power.

When I jump pins A & B the car goes into Diag. mode (SES light flashes)

When I use a 10K resistor car runs normally.

I get the same amount of data from the ALDL (19 bytes) whether pins A & B are jumped or not, 10K or not.

Only time I don't get any data is when ignition is off.

What am I missing!!!

 

Ok grounded to ALDL instead of cid lighter....same results.

I tried Craig's older software and it seemed to get 64 bytes...but still never actually displaying data look:

 

I have no idea what is going on, but mine is doing the EXACT SAME THING as the first screen shot. I am using the 2 transistor cable with a 730 ecm, pulling power and ground from the cig lighter. I too thought my cable was too long and hacked out a lot of length to see if it would help. Same results. I have tried 3 different computers with 3 operating systems 98 2000 and xp to no avail. I'm glad someone is asking the same questions!

 

When you put the 10k resistor between A&B does the idle RPM increase?

 

no it's not...idles normally....is there any specific way to plug in the 10K resistor? I know they are color coded...I tried both ways!

 

No, the colorcoding on resistors is just to identify the value of the resistor.
Try unplugging your cable, start the car and then put the 10k resistor across pins A&B, the idle RPM should raise to 1k and lock there. If it doesn't do this you have other problems, either with the ECM, prom or wiring between the ALDL and ECM (if you can read codes by jumping a wire between A&B then the wiring should be ok.)

 

OK I fixed it....turns out my soldering skills are not that great. pluging in a resistor between A & B does indeed raise the idle.

Next I grounded my cable to Pin A and drew power as always from the cig lighter....If I used the ground from the cig lighter it didn't work, so I guess this is important!!!!

Now it works.

I am SOOOO pumped!!! To bad we got snow yesterday I can't take my car out for a spin to start analyzing!!!!

 

AWESOME! Maybe the ground is my problem too! Did you ground to both the cig lighter and the A pin or JUST the A pin? Thanks

 

Just the A Pin

 

Yes, you MUST use the ECM ground on the ALDL connector for the cable. I could have sworn it was mentioned on Craig's page with the cable schematics. If not maybe we should ask him to put a note in there about that.

 

That's good news. I was not aware that this was an issue. Anyone would normally use the ground side of the cig lighter by default like we did I would think. I'll move mine and see what happens tomorrow! The note (in bold print) is a good idea.. hehe.

Since this problem has been solved, can you all help me with another issue? I would like the bootdisk to automaticly open moates software. (I dont have a working keyboard on the old laptop that I plan to use)
https://www.thirdgen.org/techbb2/sho...hreadid=171664