pcmhacking.net

Hi Guys,

Sort of new to this, been using this forum and others to research how to make my own cable, etc etc.

Car is a VY Commodore.

I went down the path of this post: https://pcmhacking.net/forums/viewt ... f=3&t=3595

Have used a 1k resistor and signal diode as per the post.

Drivers appear to be good, and are genuine up to date ftdi drivers.

Using EFIliveV4, I can pick up chatter by clicking the auto detect chatter button, and I can display ALDL chatter without issues.

HOWEVER, when I go to read the engine data and dtc's and even the other 2 macro's, I can't pick up a heartbeat.

Incidentally, when using TunerProRT the program can't detect my newly made cable when you test the cable.

What have I done wrong?


Kind Regards,
Retr0

Those boards don't really work with vx vy to slow to detect heartbeat with the very busy aldl data bus

How come other people have been able to use this and other boards using the same ftdi chip without issues? Should I really be going down the max232 path for vx and vy?

Cheers for the reply btw

Some people have had more luck than others. I havnt used this method post the ftdi clone saga, and ive recently discovered line capacitance is another thing can really mess with serial data timings while playing with a new vpw bench setup. The problem with digital signals is that they work untill they dont and its really hard to know how close to the voltage and timing thresholds you are without a scope or logic analyser. Ive seen these work and not work in threads here but no conclusive answers, sorry.

For Vr vs and high-speed comms in vn vp ecus etc they work but vx vy I can't get them to detect heartbeat with all the modules talking so can't silence the data bus to connect

The USA guys on gearhead Efi have the same issue with later model cars with extra modules and digital dashes same deal so much happening on the aldl bus that the clone boards don't respond fast enough to fire off a command in time

I've got one of these at home:

http://www.ebay.com.au/itm/FTDI-US232R- ... 0005.m1851232

If I go down the max232 chip techedge circuit will I be able to get something that works? It's supposed to be a genuine FTDI cables, I brought it years ago, never ever used it though...

It might work, but its not just the chip - how you've implemented the analog circuity is part of it too and dont rule out that there also might be a problem in your car wiring or noise on the vehicle data bus. Our interfaces have the most noise rejection if you want to rule out interface problems (most the cheaper ones are the design you link), but since your keen to make it yourself I'd say give it a shot and see what happens. Keep the wiring neat and short.

Topic solved:

In case anyone comes looking, it was the cable.