Something I came across while searching for $58 IAC pin swapping. It is more about DIY PROM but is on the Power Adder board. It is good reading for anyone converting to the $58 code.
There are a few different ways to pin the IAC I guess.

https://www.thirdgen.org/techbb2/sho...hreadid=164704

 

I played around with the 730 ECM running $58 code with a stock 1992 730 MAP wiring harness. I found that the only correct wiring for the IAC is to swap the Ahigh with the Alow pins, and the Bhigh with the Blow pins.
So www.speedtoys.com IAC wiring is correct and the others are wrong. That is, only the A and B complements when compared to $8D code and not that the A and B bits themselves are swapped.


J

 

The $58 FAQ thread seems to say swap the hi and low wires to me??? Not that a lot of discussion didn't go on to confuse the issue.

Your thread link gave me a 404 error.

So what did you end up swapping?
The 3 pins like I guessed or more?

 

The link gives me an error too. The thread is on the power adder board called something like "swapping a 730 for a 749".

After playing around with pin swapping and looking at Ludis' schematic I found this:
Using a stock 730 $8D with a stock 730 $8D harness and IAC needs the following IAC wires re-pinned when installing $58 code in a 730 ECM.

Swap the A_high and A_low pins with each other
Swap the B_high and B_low pins with each other
This equates to the www.speedtoys.com wiring pin-out for the IAC to be correct.

I tried swapping the A and B pairs and the low/high pins (as per Snap-on) and it gave the wrong IAC stepper motor direction. I tried swapping the A and B pairs leaving the low/high pins as stock. It gave the wrong IAC direction.

Anyway, doing it this way worked properly for me:
Swap the A_high and A_low pins with each other
Swap the B_high and B_low pins with each other
This equates to the www.speedtoys.com wiring pin-out for the IAC to be correct. I watched what the IAC did and it functioned the same as the 730 ECM running $8D code.

J

 

The only pins I swapped are the IAC as desbribed above.

I do not have cruise control to I didn't move that pin. I have a TH350 trans. without TCC. So I did not move the TCC pin. I do not have AIR parts so I didn't move any pins for that. No pins moved for shift light.

I do have an optical VSS in the car. I added a wire for the 730 ECM last year to pin C6 for the optical VSS. Pin C6 is the 730 ECM digital VSS input. Pin B10 on the 730 ECM is the magnetic VSS input that goes to the zero-crossing-detector and creates a digital output on the PCB.

With the 730 ECM and $8D code I had to change the PROM for the optical VSS. I dropped the $58 code in the 730 ECM and the ALDL speedo field read the same as the modified $8D bin did.
The 1618BBZB I used as a base was setup for the optical sensor from the factory.

I have some $58 code/PROM info I posted in the Power Adder board and a little bit of turbo info. It is under the "another twin turbo camaro" thread if you are interested. I am now convinced that turbos are the best bang for the buck......and you can find them at the junkyard to add to the other junkyard parts (LT1 intake, etc).

J