tunercat and freescan unable to establish communications with PCM :(

Hey guys,

I've been trying to scan and tune my 1994 LT1 m6 car with a serial ALDL interface cable hooked up to my HP dv9000z laptop through a Belkin F5U103 USB-serial adapter but it just won't establish communications with the PCM. FWIW, the laptop is running vista premium. I know the cable is good since I've used it to tune other cars before.

I hooked up the interface cable to the ALDL just like it's supposed to go on there - red wire spliced into tan wire and black wire spliced into black wire. The trouble starts when I try to read my PCM or log any data. I installed both tunercat and Freescan in Windows XP sp2 compatibility mode as recommended on tunercat's website. When trying to read the PCM with tunercat, it returns an error message that the program can't establish a link with the PCM. I have tried all available COM ports 3, 5, & 8 in options without any luck. Device Manager shows the USB adapter set to COM port 8. I found an ALDL interface diagnostic utility on TTS powersystems' website that I used to troubleshoot my setup but the interface cable passed all phases of the test. The proper driver for the USB adapter is also installed.

Does anyone have any tips or tricks for making freescan and tunercat work through a USB adapter? I was told that I need to turn off my firewall and antivirus software, but the Norton crap my computer came loaded with won't let me disable it. I'm just looking for someone to point me in the right direction, any web resources, anything...

17 views and no replies? Come one guys, I'm sure at least a few people here have had experience using USB-serial adapters.

Are you using an external power source for your ALDL cable?

Are you using an external power source for your ALDL cable?

No, this cable is powered by the USB port. I used it successfully countless times some years ago with a direct serial connection to my old desktop in my driveway.

I am pretty sure my problem is being caused by either the USB-serial adapter (which I have been told is one of two that actually work in this application) or by vista's intrusive defence mechanisms. Just looking for input from people who have had success using the same setup...

Are you saying the cable splices into the USB connector to get its power? Sorry for my ignorance, I use a different cable for my tuning and I'm not familiar with your setup.

Are you saying the cable splices into the USB connector to get its power? Sorry for my ignorance, I use a different cable for my tuning and I'm not familiar with your setup.

The interface cable was originally designed to be used directly with a serial port. The end that connects to the ALDL has three wires, black, red, & white coming out of it, and the end that connects to the computer has a serial connector on it. Since my laptop doesn't have a serial port like all new machines, I am using a Belkin F5U103 usb-serial adapter, that essentially emulates a serial port, to connect the the ALDL interface cable to the laptop. The Belkin adapter is a FTDI RS232 chip unit that was highly recommended along with another brand for this purpose.

I connected the end with the wires to the ALDL connector on the car as shown here: http://www.wotelectronics.com/install.html

The Belkin adapter is also installed using the proper drivers. Device Manager shows the device installed on COM port 8.

Bringing this thread back from the dead, but I finally got my serial ALDL interface cable hooked up via a Belkin F5U103 USB serial adapter to work with Freescan. I also borrowed an AKM USB interface cable from a friend and got it work with Freescan too. However, neither cable is reading the PCM with tunercat. With the serial cable, I got an error message saying no response from the PCM, and with the AKM USB interface cable, tunercat returns a Security Violation message. Does anybody know how I can get either cable to work?