Well, after all these years of trouble-free tuning…I’m having connection issues. Whenever I turn the key in the aux position the ECM connects to the laptop fine. However, when I turn the car on, it drops off and wont’ connect again. I did get it to connect one time with the car running, but it dropped off in 2 seconds.

I did some re-wiring of the engine harness, but the only thing that affected the ALDL port was the ground wires that I re-routed and re-connected. I checked the 165 ECM and it’s putting close to 5v, so that shouldn’t be the problem.

I'm using TunerPro V5, moates cable, etc....

I did a search and didn't come up with anything substantial. Has anyone dealt with this??

 

Your alternator might be putting out too much electrical noise. Try unplugging the alternator plug and see what happens. You only need to unplug the one plug for this test, you don't need to disconnect the alternator output lead.

Your engine won't be charging the battery during this time but for just testing it should work for you.

 

Ok, I'll try that when I get home. If that is the problem, what's the fix?

 

Well, I got home and tried your suggestion.....didn't work. Thanks for the input.

What would cause the ECM to drop off on starting the engine? Voltage conflict? Reversed wiring?

I'm stumped......

 

bump...

 

Worked before you did this and now wont after? If so theres your issue

 

Yep, I'm sure that is my general issue.

I was just trying to nail it down to something a little more specific. Like what to look for in my wiring harness. If it didn't connect at all, it would actually be easier....but it's conditional.

 

Not sure what all you changed but 165's are notorious for being flakey on connections. I spent hrs on one car one day and couldnt connect. Next attempt a few days later it was connecting fine. Then a day at the track it didnt work or disconnect after few seconds. No idea

 

Yeah, I saw your post about that. I was actually having that problem right before I re-did my harness, just didn't think anything of it. I definitely have had more connection issues once I upgraded to my new HP laptop with Windows7.

I would like to try a spare 165 ECM and see if that's my problem. I bet it's pretty simple.....just gotta figure out where to look.

 

I take it that you are using a serial to USB adapter cable. The HP laptops with WIN7 don't have FTDI USB chip set drivers installed correctly. Backing them out and doing a fresh driver install is recommended (http://www.ftdichip.com/Drivers/VCP.htm).

The EBL systems use a higher data rate then the ALDL links, so not sure how much this next statement means. Many of the less expensive serial to USB adapter cables can't keep up with the high speeds and fast turn around times.

For the EBL, the popular (cheap) Prolific adapter cables don't work. The cables that use the FTDI chip set cost more, but they work 100%.

Not sure if this is the issue but it is worth mentioning.

RBob.

 

I'm using the Moates cable, I would think their stuff should work. Once I got my laptop, it used to connect after a few attempts and stay connected. It seemed to get progressively worse, to the point I could only data log for about 5 min and it would disconnect and couldn't re-connect. Maybe I'm dealing with a combination of issues.

Which cable do you recommend from the FTDI website?

Thanks for your input.

 

Well this isn't a direct step forward but the laptop should never connect with the key in the AUX position. The ECM is off when the key is in the AUX position. So did you mean the AUX position or did you mean key on engine off? If you meant AUX does the laptop connect in the RUN position but the engine off?

 

Yes, I meant the laptop connects key on and engine off. My key doesn't work in any other position, so I was calling it AUX.

 

IF the cable is direct from ALDL to USB then there isn't a separate serial to USB cable that you can use. Craig used FTDI parts in the past, so I'd guess that he used them in his ALDL to USB cable.

Can check by going to the USB port Properties dialog, Port Settings tab, Advanced button. Center left there should be a BM Options box with a latency setting. If so that cable is using a FTDI chip.

RBob.