someone972

iTrader: (2)

So I've been trying to get Tunerpro to interface with my 1991 Firebird Formula 5.0L TPI. I'm using the 7730 adx file with the 8D mask. The cable is a diy two-transistor setup going through a usb-serial converter. When I try and connect with TunerPro it just stays on DA: Connecting. I've scoped the M line, and it's sending a short waveform over and over but the car never responds. The circuit brings the 5v all the way to ground when sending bits, so it's not a voltage thing. The car does the standard blink codes just fine. Unless someone has an idea of what a good waveform for the packet looks like, I'm not sure what to do. I may try and find a dealership that still has a OBD1 scanner to see if my computer will interface with anything at all.

Veaceonee

iTrader: (1)

I got Tunerpro to interface with my car once, never again. I use WinALDL.

Are you sure the cable is good?

WinALDL has a connection number window thing that tells you how strong the connection to the car is. Try using that and wiggling your adapter in the port. I have to do that sometimes.

someone972

iTrader: (2)

Doesn't WinALDL only work with 160 baud? My car doesn't even have a terminal for that, it only has the 8192.

L98_383_Stroker

What kind of scope do you have? Can you upload the waveform screen capture? Did you verify that the USB-Serial converter is at 8192 baud by looking at the width of the bits in the waveform? If you see the bit stream, I bet it is 9600 baud.

Open up the adx file and look for the message it sends. Post the hex numbers up here and I can look through some ALDL info I have to verify the correct message is being sent!

Also, what converter are you using? There is a video on youtube where a guy makes a cable from an FTDI RS232 chip. You might want to give that a view. It is a simpler design than the transistor circuit.

Good luck!

someone972

iTrader: (2)

I'm going to go pick up a USB-Serial converter that supposedly works with non-standard baud rates including 8192. I'll compare the waveforms and post the results up here if I get time. Hopefully it works, but if it doesn't at least there's people here that know what they're doing!

someone972

iTrader: (2)

Yep, it was just as you thought. My old converter was running at a higher baud rate than the new one. The waveform for the old one was visibly shorter, and hooking the circuit up with the new converter to the car it connected right away. I'll post the images for the waveform before and after if I get some time in the next few days, just in case anyone is curious.

L98_383_Stroker

Awesome! Glad to help! Good luck!