Jump to content

Honda RACV control problem


Recommended Posts

Hello Scott. I finally managed get my engine running smoothly with my G4 Xtreme, but there's still a fly in the ointment.

I'm trying to use a 3 wire Honda RACV that looks like this: http://i130.photobucket.com/albums/p254/bazwouterze/Honda Civic/DSC00876.jpg

To do this, I set Aux Out 1 to ISC Sol Slave and Aux Out 2 to ISC Solenoid, with a frequency of 500 Hz. With Idle Control in Open loop, nothing that I enter in the Duty Cycle table has any effect. The engine idles really high like the RACV is fully open. I kept changing ISC Solenoid frequency all the way from 20 to 500 Hz, and nothing worked. Connected another RACV that I had lying around to see how the shutter behaved, and for frequencies above 20 Hz, I don't hear or feel the solenoid buzz like it should. Even when it clicks rapidly at 20 Hz, it is unable to control idle.

I have a good mind to fix a 2 wire IACV there, but would really like to run the RACV. Any suggestions?

Link to comment
Share on other sites



There are some later model solenoids that are 3 wire but they run like a 2 wire unit.

The connections are then Power, Ground and a signal

To confirm this you would need a wiring diagram for the car it came off or measuring on a working car/engine.


Edited by Simon
Link to comment
Share on other sites

I think this page has info on the idle solenoid you are using:


Looking at the schematic image it appears that the idle solenoid might need +12V(ign switched), an ECU postive control, and an ECU negative control. If this is the case I think our ECU will not be able to control it, as our ECU outputs ground on aux 1 and ground aux 2 to move the solenoid in opposite directions.


Link to comment
Share on other sites

I believe this IACV requires a PWM ground signal on both pins besides the +12V pin to move the shutter in opposite directions. Let me try to scope the stock ECU's control signals versus the Link and revert.

Edited by 007
Link to comment
Share on other sites


Again, it was the default settings that did me in. The max and min clamps in the IACV settings were holding the commanded duty cycle back.

The IACV works as I guessed before. Unpowered, the shutter is halfway open and that is where it returns to rest once any applied signal is removed. Grounding the IACVP pin rotates the shutter one way and grounding IACVN rotates it the other way. 50% duty cycle keeps the shutter at its default position. Anything above or below 50% either increases or decreases idle depending on how IACVP and IACVN are wired.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...