IAC question.

[wallace18]

The IAC for the K818S build is inop. I took it apart and found it seized up with carbon. Very common from what I have heard. But the 3 connections to the motor ohm out open circuit on all of them . Should there not be resistance in the windings? I think the IAC is shot but before I buy one I want to be sure. The factory manual is useless to diagnose this thing. Thanks for any help from someone with experience on Subies. TW.

[twgab]

If you don't have it figured out by tomorrow, I'll see what mine reads on my wrx.
Mine was shot on my 818 as well, but I just swapped it out with my daily driver. Worked out well on my first start as it stayed at 2000 rpm's, I had new cams, and needed to keep it there for 20 minutes.

[metalmaker12]

Clean out and put on a new gasket to start. A lot of times the gasket gets stretched and it becomes full of crap. Most of the time they work well again. Unsure of the resistance but if it was not gathering power or a signal your check engine light would be on with cel p1507.

[xxguitarist]

I see 65k between the two lower pins, otherwise yes, it's OC at Mohm scale, on our 02 WRX.

[wallace18]

Clean out and put on a new gasket to start. A lot of times the gasket gets stretched and it becomes full of crap. Most of the time they work well again. Unsure of the resistance but if it was not gathering power or a signal your check engine light would be on with cel p1507.

I have cleaned the unit and will double check the wiring. The gasket was fine. But I will install a new one. I do get the 1507 code and the engine goes into a fault mode and cuts out cylinders at idle to keep idle down. I can not find any air leaks either. This build has been trying my patience to the max for sure.

Thanks to all for their help, it is very much appreciated.

[twgab]

I'm getting about the same as xxguitarist, 61k between bottom & middle, open everywhere else. Hope that helps.

[wallace18]

I'm getting about the same as xxguitarist, 61k between bottom & middle, open everywhere else. Hope that helps.

Yes that helps. I have double checked the wiring and it is all correct. Pin 1 goes to pin 10 B136 of ECU, pin 3 is an engine ground and pin2 is power from main relay. So I should be good when I get the ecu back. Thanks to all again.

[metalmaker12]

I have cleaned the unit and will double check the wiring. The gasket was fine. But I will install a new one. I do get the 1507 code and the engine goes into a fault mode and cuts out cylinders at idle to keep idle down. I can not find any air leaks either. This build has been trying my patience to the max for sure.

Thanks to all for their help, it is very much appreciated.

Check connector, if you have and it's wiring prior, check previous connector etc. They can get funny over time, use some de electric grease, and good luck

I am sure you know all this, just throwing it out there.