Help, Code 24.

[CAV3MAN227]

-Okay, so I cannot get rid of code 24 which is, Air control valve: Air control valve inoperative (Abnormal signal produced in monitor circuit)
-This is what I've tried. At the beginning the wires were brittle so I got another clip and swapped it out. (Just to make sure we're on the same page here's a pic: http://hostthenpost.org/uploads/b34a72a ... d8f9e2.jpg ) When the car was on and the head was loose, moving it clock-wise and counter clock-wise wasn't doing anything, so then i swapped out the head of the IAC put it back together and tried again and now it does mess with the idle but code 24 is still there. Tried resetting the computer multiple times and code 24 keeps coming back. even tried with another ECU, mine: http://hostthenpost.org/uploads/a9e25a9 ... de019f.jpg , donor: http://hostthenpost.org/uploads/e233a1c ... 4cd0a2.jpg Checked it with an ohm/volt meter and all, had the proper specs as listed on Legacy777's site... code 24 still there! Its the only code I have left to clear out of the other 3-4 I had.
-If you have any ideas to this, any help is greatly appreciated!

-Thanks, Joe

[CAV3MAN227]

-Also here is a video of the car and how its acting after resetting the computer, just before the fans turn on for the first time. Click to watch! It was idling about 1,000rpms.

-The fans turn on just before the end of the video!

-Joe

[CAV3MAN227]

-Bump!!!
-Anybody? I'd really like to get this issue resolved!
-Joe

[Apex3]

You tested the IAC or the ECU? Have you tried a different IAC?

[CAV3MAN227]

-I tested the IAC. I have tried a different IAC head but not the whole unit.
-Joe

[cj91legss]

i think you should just try a whole different IAC

[HappyFrog]

When does it throw cel? All the time or just occasionally? Mine kept coming on if engine braking at low rpm. If I took it out of gear and let it idle a second or two, cel would go away. Never found out what it was and the problem went away when I had the aftermarket ecu fitted.
I tried another iacv and tps before the ecu was changed, it didn't fix it. On a side note it turned out I had bad spark plugs and real crappy wires, but I dunno if it was part of the problem.

[CAV3MAN227]

-Well after having the battery disconnected for a few hours then connect it back up, the CEL will come on before you even start the car. A friend of mine thinks its wiring but doing tests with an ohm/volt meter the numbers are correct. But I think that is my next step is just to replace the whole IAC unit with another and see what happens.
-Thanks for the help, anymore ideas I'm all ears!
-Joe

[Legacy777]

When you say you tested the wiring and the numbers are correct. Can you elaborate on what exactly you mean by that? Does all wiring have 0 ohms when checking them? What happens if you jiggle the wires around? Does the resistance value change?

[CAV3MAN227]

-Just testing each wire, read 1.4 ohms. Resistance value stays the same. That was with the ignition on, car not running. I have not tried jiggling the wires around! I can test that soon!
-Joe

[91legacyawdturbo]

Olms on the car are at zero so there's not a break or short within the harness specs are 1.4 Joe knows the olms. The iacv specs are the same voltage as mine. I have no clue why it's not going off. The car acts fine but just has the light.

[Apex3]

Ohh, just the light? But it does throw the code still right? I thought you were having problems too, try unhooking the battery over night maybe.

[CAV3MAN227]

Ohh, just the light? But it does throw the code still right? I thought you were having problems too, try unhooking the battery over night maybe.

-been there done that!

[Legacy777]

What happens when you connect just the green diagnostic connectors? Does it display an initial code or does it blink all clear?

[91legacyawdturbo]

Neither just keeps blinking that same code, which tells me there is an issue with the iacv, wiring, or maybe by chance the ecu. the code will not clear,The problem in general makes no sense.

[Legacy777]

Typically if there is a code stored, when placed in d-check mode it will not immediately blink the same code as the problem. Have you followed the d-check procedure all the way?

I've heard of someone that had a code that wouldn't go away until they did either the d-check procedure or the memory clear with the black & green connectors.

[91legacyawdturbo]

D-check???

[Legacy777]

www.surrealmirage.com/subaru/engine.html

Read that first section. It talks about checking codes and the d-check.

[CAV3MAN227]

-So today for the hell of it, I tested the a, b, and c wires coming off of the IAC with a test light. When touching the c wire, it lit up the test light and brought the idle to normal. Not sure what that means but sounds like a bad ground.
-If it is a bad ground can I just run a wire from c to the block or frame somewhere? Or do I need a dedicated wire from the ECU to the IAC, c terminal?

-Joe

[CAV3MAN227]

-I don't understand this diagram and what its saying... http://hostthenpost.org/uploads/5aa3d09 ... 97fb4a.png
-I think there's a wire crossed.
-When key is in the on position, motor off, B (red and yellow wire) is the only one that has power. with the motor running all 3 have power. is that how its suppose to be? or isn't one ground and only 2 of the 3 should have power?

-Joe

[Legacy777]

The way the IAC valve works is it takes a 12v switches source on pin 2, and then the ECU sinks or grounds that to open or close the IAC valve. So that crazy routing of the pin 2 wiring is just going to a 12v ignition lead.

Pin 2 should have 12v on it. It's possible if you have low voltage on the IAC valve on pin 2 it may not be working the way it should.

[CAV3MAN227]

-Well the yellow/red pin 2 wire had 11.93v so its getting power. My question is, what are the black and white wire suppose to have?
-I think I've came to the conclusion that this has gone on too far. Today I re-wired the damn IACV once again and still no results. As far as I can see, I need to run some dedicated wires from the ECU to the IACV. I'm having trouble reading some of these wiring diagrams from Legacy777's website, but I would love to get my hands on some instructions to run these 1, 2, or 3 dedicated wires! Any help is greatly appreciated!
-Joe

[91legacyawdturbo]

Finally you get what I've been telling u just get off ur bum and check the ground to the ecu!!!! Thank you

[SLODRIVE]

Did you check/repair your TPS wiring yet, or check the connections where your AVC-R is wired to the ECU? If you remember, it wasn't giving any readings through Evoscan.

[Legacy777]

-Well the yellow/red pin 2 wire had 11.93v so its getting power. My question is, what are the black and white wire suppose to have?
-I think I've came to the conclusion that this has gone on too far. Today I re-wired the damn IACV once again and still no results. As far as I can see, I need to run some dedicated wires from the ECU to the IACV. I'm having trouble reading some of these wiring diagrams from Legacy777's website, but I would love to get my hands on some instructions to run these 1, 2, or 3 dedicated wires! Any help is greatly appreciated!
-Joe

Joe,

When dealing with chips, they don't do well sourcing or providing power to devices. However they are much better at sinking or being the ground. So for the IAC valve, the battery provides 12v power through a relay to the center pin of the IAC valve. The two other pins go to the ECU. They are connected to a transistor and the ECU will activate or ground each side of the IAC valve through separate transistors pulling the valve open or closed. Since this is happening so fast, it's called a duty percent.

So those other two wires going to the ECU are essentially going to ground, but are doing it through a switch in the ECU.

Make sense?