I have recently swapped my engine with the same model (D16Y8) and had help from a friend as I had never done it before. I had him plug everything in and it turns out that he plugged a few things in wrong. I drove for a month with the CEL on, but to make a long story short I'll get to the point. He had plugged in the 2PIN connector for the IAC into the PSP and vice versa. When I finally noticed it I switched it back but I have the code P1508 (IAC Circuit Malfunction). I have followed the instructions in the service manual which included testing the 2 pin connector for voltage which had 12V. A12 to ground also had voltage (10). The IAC clicks when jumping A10 and A12.

I have also cleaned and replaced the valve with another. Is there another connector that may be plugged into a wrong spot that can cause this? I have a manual transmission (5 speed)

I have spent so many hours trying to solve this and have searched COUNTLESS forum posts and have not found a solution. If anyone has any help it would be much appreciated.

 

Have you reset the ECU?

 

More times than I can count. I've even taken the case off of he ecu to check for any burning on the board

 

The connector swap mistake may have blown the ECU. Swap in a known-good ECU and go from there.

 

Bump.

So I got a new ecu and IAC and the problem persists. I checked for continuity on the yellow/black from the connector to the ecu to the connector going into the IAC. There is continuity. Now for some reason other is no continuity between the blue/black on the IAC side to the ecu side, however if I test the blue black on IAC side to the yellow/black on the ecu side there is continuity. Any reason for this? Also another thin to mention which I don't before is that the motor that I put into my car came out of n automatic an I had o swap fly wheels on the engine because my car is a stick. Is there any difference with wiring on these two motors? Both are the same model

EDIT: quick question with the harness. Is there a middle point on the harness that unplugs so that I can check for continuity there and possibly narrow down where a problem might be, if any.

 

Bump

 

I'm dying here guys, help me out

When I did the swap I had to switch intake manifolds as well. does the automatic vs manual intake have different specs for the IAC?

 

7 months later and you're just mentioning that? Anything else you might have forgot to mention? It might be critical.

 

No, that's it..

 

Do you have any suggestions grum? Do you know if the manifolds are different when it comes to IACV?