Uber-easy DIY USB ALDL Cable

[billymild]

I am working on creating my own ALDL USB cable for my ZR-1. I bought a FTDI USB cable off Ebay and a 12 pin to 16 pin convertor cable. I cut that in half and am trying to hook up the FTDI USB cable to the 12 connector. Issue I see thus far is the 12 PIN connector cable only has 4 wires. They are BROWN, RED, ORANGE, YELLOW.Does anyone have any idea what wire is ground?

[simon blazer]

I am working on creating my own ALDL USB cable for my ZR-1. I bought a FTDI USB cable off Ebay and a 12 pin to 16 pin convertor cable. I cut that in half and am trying to hook up the FTDI USB cable to the 12 connector. Issue I see thus far is the 12 PIN connector cable only has 4 wires. They are BROWN, RED, ORANGE, YELLOW.Does anyone have any idea what wire is ground?

you can check it with multitester right?

[billymild]

you can check it with multitester right?

I found this picture which helped out a ton.

[simon blazer]

Hi guys, I've made 4 type of ALDL obd1 cable :

1. with RS232 to TTL, Tx and Rx tied together on the TTL side, and connect into pin 9 (ALDL 16pin), cable found and functioning, passed cable test, but still cannot talk to ECU.

2. with TTL to USB adapter (FTDI chip), Tx and Rx tied together on the TTL side, and connect into pin 9 (ALDL 16pin), cable found and functioning, passed cable test, but still cannot talk to ECU.

3. Built 2 transistor interface, no cable found, no talk to ECU
4, Built 1 transistor interface, no cable found, no talk to ECU

It's seems tha my ECU not listening to them, but it's talk happily to GM tech 1 scanner for sure.

What else I can do to make ECU talk to me? thanks for help.

arduino_rs232.jpg


Best,
Simon

[donf]

As a new user I read through all 26 pages and if i am understanding it correctly the majority of problems since about 2014 seems to be driver compatibility with the boards with bootleg chipsets? In considering either to build a cable or buy one, I noticed on seller on eBay said

Utilizes a genuine FTDI chipset, FT231XS, not the FT232RL which is being counterfeited in Asia. The counterfeit chips have been rendered non-functional by the latest FTDI driver.

So is a board based on the FT231X a better starting point in 2017 for a DIY ALDL than the Arduino FT232RL recommended at the start of this thread 5 years ago? They are not as easy to find, but I just wanted to get opinions if a cable project should now use a different chipset to prevent some of the headaches.

[-=Jeff=-]

I know this will work..
https://www.sparkfun.com/products/9716
I had one with one of my arduinos and tried it on my 90 corvette.. tie both RX and TX together and it worked great with ALDLDroid..

[Chewy1576]

I know this will work..
https://www.sparkfun.com/products/9716
I had one with one of my arduinos and tried it on my 90 corvette.. tie both RX and TX together and it worked great with ALDLDroid..

I have this board also. Works perfectly with 16197427 and TunerPro.

[EDZIP]

I know this will work..
https://www.sparkfun.com/products/9716
I had one with one of my arduinos and tried it on my 90 corvette.. tie both RX and TX together and it worked great with ALDLDroid..

Anyone have the schematic that ID's the diode size, resistor size and pin outs for this board - for a 94/95 LT1 "16 pin" connector?