GaryDoug

You will need to trace the wires with an Ohmmeter (part of a multimeter). The wire that goes to pin A is the same as the black wire originally, so label that wire as "A". The wire that goes to pin M is the same as the brown/tan wire originally, so label that wire "M".

Theo96

Okay @GaryDoug calling on you again...
I've made the harness and I initially got the "a device which does not exist was specified" error
So, it looks like I'm going down the driver rabbit hole.

I'm afraid I bought the wrong USB...It came with TXD, RXD, VCC, and ground cables, so I assumed it was correct.
This is what I bought: PL2303TA USB to TTL RS232 COM UART Module Serial Cable Adapter for Arduino | eBay

Is that correct? And if so, do I just download the latest driver?

Thanks

GaryDoug

Wrong cable. That one will not work for the GM cars. It MUST be the FTDI type. Example:
The one above will work. Many similar 5V ones will probably work and are cheaper but you take a chance with them. Do not get a 3.3v one.

GlenDailey

Hello Gary,
Like most of the previous posts, I am most appreciative of your work, and impressed with your donation to the cause.
I'm in the process of grafting a 95 Camaro 3.4 engine and trans into a 1970 MGB (this is a common engine swap).
I've got it running but would like to use the tool that you developed to monitor and manage the engine.
I've purchased the USB cable you recommended above from Amazon (Gearmo), but it does not have a white wire.
I have tried using the green and orange combination that you suggested in a previous post, but that does not seem to work.
I'm using an older laptop with Windows 7, and have loaded the FTDI .28 drivers per your instructions.
The loopback test yields zero results, so it appears my cable is not correct.
Any other ideas as to the correct wire colors for Tx/Rx?
Thanks much,
Glen

GaryDoug

See the ad again. It shows the pinouts for the 6 pin connector on the end. You will use the TXD and RXD tied together (pins 4 and 5). The Gnd (ground) is the black wire on pin #1.

1994-LT1-Eric

I may have missed it, or not seen it compiled in one list - but is there a list of nominal sensor values for the different cells in the logs? (Was thinking both open and closed loop)

It'd help with troubleshooting for sure. I've been taking notes on what values I'm familiar with.

Injuneer

Have you looked at my scanning guide? Sticky at top of this forum. Doesn’t cover every column, but hits the critical sensors, fuel corrections, etc.

1994-LT1-Eric

Of course I haven't lol, I will now though - didn't even realize it was there. 🙄

rustv8

i am not sure if i had asked this before but what voltage and ohms am i supposed to check for for a code 36 ,on a 95 camaro brand new optispark by petris, new acdelco coil ,msd wires, new icm, hesistation at 2000 rpm then flies, idles abit wierd.

Injuneer

To check the circuits from the PCM to the Opti, use Shoebox's instructions, scroll down to “OptiSpark Harness”. Note that test is done with the harness connector off the Opti. If you don’t have 5 volts between pins B and D, the problem is either the PCM, or harness/connectors. You have to test the harness end closest to the Opti. I don’t know if the Petris has a permanently attached “short Opti harness”, or if it uses the factory short harness.

4th Gen LT1 F-body Tech Articles

To check the high res signal from the Opti, with harness connected, put a scope between harness pins B and D. Should see a 0 to 5 volt square wave.

http://shbox.com/1/95_ign_system_schematic.jpg

I thought a posted some of this yesterday in response to the question you tacked on to the old DTC 36 thread in LT1 Related Engine Tech, but I don’t see it today.

Lacking a scope, put a DC volt meter across those pins and rotate the engine very slowly, looking for the voltage to switch back and forth between 0 and 5 volts.

http://shbox.com/1/95_ign_system_schematic.jpg

Injuneer

Actually, I did respond yesterday, apparently you didn’t bother to go back and read it.

https://www.camaroz28.com/forums/lt1...3/#post7012337

You need to keep all your posts on the topic in one thread. You now have it in three threads. Pick one and stick with it.

rustv8

deleted.

Injuneer

This discussion does not belong in this thread. The thread is about Scan9495. Not sure why this is so hard to understand.

rustv8

hey how do you show the voltage for the high resolution or low resolution voltage or statistics on the application? i have a 95 camaro and i looked in charts looking for it in the drop down for one of the charts?

GaryDoug

Those are only available for a 93 engine. The closest thing for the 94/95 is the RPM (low res only).