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-   -   IMRC Flaps won't stay closed during vehicle operation (https://www.focusfanatics.com/forum/general-technical-chat/812533-imrc-flaps-wont-stay-closed-during-vehicle-operation.html)

[email protected] 04-28-2019 08:31 PM

IMRC Flaps won't stay closed during vehicle operation
 
2010 Focus Auto Trans 230,000 miles.

Does anyone know the IRMC control logic and specifically the components that contribute to the ECU providing the ground signal to the vacuum solenoid.

I have no CEL or stored codes but I can tell by opening the hood and looking that my IMRC Flaps are open almost all the time when they should not be. I even put my Go Pro under the hood to watch the actuator during driving.

When I start the car cold the actuator cycles from open to closed to open then back to closed after a few seconds just like it should. After I drive the car about one mile the IMRC flaps go back to open where they stay until I shut the car off and then they cycle again like they should during shut down. If I restart the hot car the actuator cycles from open to closed to open like it should but then instead of going closed again they just stay open.

So on a cold start the flaps function normally until the engine warms slightly. On a warm start the flaps fail open immediately after the start up flap actuator cycle test.

At any time after the flaps have failed open, if I provide an external ground to the vacuum solenoid the flaps close and stay closed as long as I provide the external ground, even while driving the car at various speeds, over bumps, cold and hot.

For some reason the ECU is removing the ground signal from the vacuum solenoid as the engine warms up.

Does anyone know the IRMC control logic and specifically the components that contribute to the ECU providing the ground signal to the vacuum solenoid.

Again, I have no diagnostic codes and the vehicle performs OK except I am getting 3-5 fewer mpgs than I used to. In fact I just passed emission testing with the system malfunctioning as described, on Friday.

The online wiring diagram I found does not show me how that ground signal makes its way to the vacuum solenoid.

Once again, Does anyone know the IRMC control logic and specifically the components that contribute to the ECU providing the ground signal to the vacuum solenoid.

Thanks, Mike

Marde 04-29-2019 02:53 AM

Major bummer that you still have a IMRC problem after your recent fix of 5-Volt output of the PCM was too low. For the record, your old thread about IMRC and low voltage is here->
https://www.focusfanatics.com/forum/...nsor-2-0l.html

Quote:

Originally Posted by [email protected] (Post 11376259)
...Does anyone know the IRMC control logic and specifically the components that contribute to the ECU providing the ground signal to the vacuum solenoid.

Sorry, no, I don't know. I did offer you some good guesses about "IMRC control logic" in your prior thread.

Quote:

Originally Posted by [email protected] (Post 11376259)
...
I have no CEL or stored codes but I can tell by opening the hood and looking that my IMRC Flaps are open almost all the time when they should not be. I even put my Go Pro under the hood to watch the actuator during driving.
...

That is crazy strange. The IMRC failure (that you can see with eyeballs and the GoPro camera) should cause a P2004 code. Why you have no DTC CODE today is very-very strange.

Quote:

Originally Posted by [email protected] (Post 11376259)
...
When I start the car cold the actuator cycles from open to closed to open then back to closed after a few seconds just like it should...

"Like it should"??? The IMRC actuator operation you described is not normal, based on my 2004 car, the IMRC does not operate like that. My car engine is IMRC OPEN while engine off and goes to CLOSED when I start the engine and stay at idle. There is NO open/closed/open/closed cycles like you described. That behavior sounds abnormal, even for your 2010 car.

Please re-read my original post in your first thread (at post#3) about this subject. I think you might have a vac hose leak despite your vac tests. Here is part of that post...
Quote:

Originally Posted by Marde (Post 11372847)
...My first guess is that you have a vac hose leak DESPITE the external vac test equipment that you used. Did your vacuum test include all the vac hoses in this system? I know (first hand) that some vac leaks can be hidden from the naked eye. Some vac hose damage is only seen once the hose is removed from the car; to release & relieve the hose of its' typical old positioning while installed in the car...

Maybe your external test-equipment vac tests pass ok, but maybe you are not testing-considering ALL hoses OR all these hoses when warm-hot.

Side Note to Mike: you kept repeating the typo IRMC verses IMRC. Darn acronyms get mixed up easily.

[email protected] 04-29-2019 11:06 AM

I think that the cycling at start and stop is normal and that is the system checking itself and that is why there are no diagnostic codes. My theory is that the system does not check IMRC (correct spelling, thanks) during vehicle operation, just at start and stop. The cycling is perfect every time, seems like it is programed to do so. Which I had another car to observe this one. I will be on the lookout for one. Maybe test drive one on a used car lot today to verify.

It really can't be a vacuum issue because when I supply an external ground directly to the vacuum solenoid the flaps close instantly and stay that way al long as the external ground is applied. It seems to me that the fault is in whatever path that ground signal to the vacuum solenoid takes to get from the ECU to the solenoid. From the wiring schematics I can find online it seems like the EGR valve is in the mix somehow along with the cylinder head temp sensor and of course some engine rpm signal. The EGR valve is cheap ($20) so I was thinking of replacing that.

I know that I should probably just leave it be and drive it but I am very curious what is causing this and the extra 10% in fuel economy would save me $200/year.

Many thanks for all of your comments and time. I'll keep poking around a bit. I am surprised that I have been unable to find a detailed description of the control logic in the online service manual?? Maybe Ford considers this info proprietary??

Anyhow again thanks, Mike

Marde 04-29-2019 09:35 PM

Quote:

Originally Posted by [email protected] (Post 11376377)
I think that the cycling at start and stop is normal and that is the system checking itself and that is why there are no diagnostic codes. My theory is that the system does not check IMRC (correct spelling, thanks) during vehicle operation, just at start and stop...

If that cycling behavior is normal is TBD. My prior comment was only that my 2004 car does not do that cycling behavior at start-up.

I do not share your thoughts, in your theory. I believe IMRC is continuously monitored. As mentioned in your first thread, the IMRC does not attempt to recover or re-engage after a failed state occurs UNLESS you turn the engine off, key-off.

Quote:

Originally Posted by [email protected] (Post 11376377)
...It seems to me that the fault is in whatever path that ground signal to the vacuum solenoid takes to get from the ECU to the solenoid. From the wiring schematics I can find online it seems like the EGR valve is in the mix somehow along with the cylinder head temp sensor and of course some engine rpm signal. The EGR valve is cheap ($20) so I was thinking of replacing that.

You already have the needed wire diagram, from Paul, in page-1 of your first thread. It shows a direct wire path from the solenoid (pin-2) to the PCM C175T Pin-22. This wire is BLUE. This is your Solenoid "grounding wire". If your were to monitor this wire during operation, you would see this signal Hi (at 12 to 14-Vdc) while flaps are Open ((solenoid not grounded)) and signal Low (near 0-Vdc) while flaps are Closed ((solenoid grounded)).

The EGR is not "in the mix" except for a shared supply voltage. There are several components that share this (12 to 14 Vdc) voltage. The IMRC Solenoid shares this supply voltage. Do not replace the EGR valve...unless you can explain why you believe it is in the mix.


Quote:

Originally Posted by [email protected] (Post 11376377)
...Maybe Ford considers this info proprietary??

Maybe so. System Description Documents or technical descriptions are rare in general. Nothing good for them, if they shared this stuff with the public. With my tiny bit of Service Manual exposure, I remember reading HOW TO FIX info, but do not remember any or very little system description info. Also, I have never(?) seen any detailed technical docs for Ford PCM systems or a Functional Diagram that might explain what you want for the IMRC. However, I have seen lots of this stuff in Aviation.

Unique exception - The (Ford) 4F27E Transmission Service Manual - not written by or distributed by Ford, has lots of tech descriptions.

The info you want, might be a good question for Tom. He might not have IMRC Logic info, but he knows his way around the PCM Logic subject in general. Send him a PM and/or call him during business hours.

FF User name = 1turbofocus (Tom)
Customer Support
AIM: hpdyno
Email: [email protected]
Phone: 704-249-3745
Site: focus-power.com

[email protected] 04-29-2019 10:32 PM

Marde,

Many thanks for your comments. I thought that I was grounding the green wire on the IMRC solenoid to close the flaps but in fact I was grounding the blue wire as you pointed out was correct per the schematic in earlier posts. In this process I unplugged the connector to the solenoid and re-plugged it in.

After that I tried to take a video of the cycling at start up and shut down I spoke of earlier and it did not cycle this time. It went closed at start up and stayed closed. When the engine revved to 3,000 or so rpm the flaps opened as they should and then closed when rpms were reduced. This was the first time in a long time the flaps functioned properly.

I will investigate connections closer tomorrow and check the ground wire between the ECU and the solenoid but it now seems like a connection issue in that ground wire.

Again many thanks for your input!!!

Mike

Marde 04-29-2019 11:41 PM

Info in your last post suggests that there might be a wire problem at the connector at the IMRC Solenoid. Maybe the wire contact-pin "crimp-point" for this PCM ground wire is messed-up OR at this same area where the male-to-female connectors join at the IMRC Solenoid. Clean-up those (male and female) electrical contact pins, and make sure they seat together (are clean & snug) once the Solenoid connector is connected.

I know you kinda said this same thing, but I wanted to repeat your words, to ensure we both see this potential problem the same way.

Glad to hear your actuator "cycling" symptoms during engine start-up disappeared in your most recent test. Things are looking up. Cross fingers.

[email protected] 04-30-2019 01:58 PM

OK so I checked connections and wiring and all looks good. Just for the heck of it I replaced my IMRC Solenoid for a third time with no change in operation. While my IMRC system did function properly for a brief time yesterday (once to be exact), today it consistently does not.

I used my Go Pro to make an under hood video of the actuator opening (up) and closing (down) and made an index of the video below to identify what was going on with the car during each time slot.

If anyone has insomnia and wants to be bored to death, here you go.

The video is on Youtube at this link:

0:0 0:11 Cold engine start and begin to back out of garage
0:47 3:58 Flaps open while driving at 0:47 (may have hit 3,000 rpm) and then they stay
open until engine stopped at 3:58
4:00 4:15 Hot engine restart, flaps open, rev to 3,000 rpm, flaps stay open, then engine
stopped, flaps close
4:18 4:32 Hot engine restart, flaps open, engine idled, flaps stay open, then engine
stopped, flaps close
4:33 4:46 Hot engine start, flaps open, rev to 3,000 rpm, flaps stay open, engine left
running.
5:00 5:55 With engine still running, open hood and wiggle wiring connections at PCM, at
IMRC Module and IMRC Solenoid, flaps stay open.
6:02 6:08 Engine stopped, open flaps cycle to closed then back to open.
6:11 6:18 Hot engine restart, flaps open, engine idled, flaps stay open, then engine
stopped, flaps close
6:21 6:29 Hot engine restart, flaps open, engine idled, flaps stay open, then engine
stopped, flaps close
6:50 7:44 Hot engine restart, flaps open, engine idled,. Then externally ground blue wire
to IMRC Solenoid, flaps repeatedly close when externally grounded and open
when external ground is removed.
8:00 8:42 With external ground still applied to IMRC Solenoid, hot engine running and
engine revved to 3,000 rpm, flaps stay closed, till engine stopped then they
open.
8:43 10:00 With external ground still applied to IMRC Solenoid hot engine, start and
drive home, flaps stay closed.

Generally it seems that on a cold start the flaps close as they should but the first time they open at 3,000 or so rpm they never shut again until the engine is switched off. On a hot start the close for a second when the ignition switch hits the run position then they open and never close again until the engine is switched off. There are no diagnostic codes.
I am thinking it is a bad PCM.

Marde 04-30-2019 11:48 PM

Quote:

Originally Posted by [email protected] (Post 11376691)
...
Generally it seems that on a cold start the flaps close as they should but the first time they open at 3,000 or so rpm they never shut again until the engine is switched off. On a hot start the close for a second when the ignition switch hits the run position then they open and never close again until the engine is switched off. There are no diagnostic codes.
I am thinking it is a bad PCM.

Your video confirms what you have previously said about the faulty & strange behavior of your IMRC system. Hot verses Cold engine "IMRC failure behavior" is also strange. Why there is no P2004 DTC kinda blows-up my mind.

I am starting to cave-in to the idea that the PCM is bad. Maybe the PCM experienced an internal failure during the prior problem. When the PCM 5V system was strangled by the faulty power steering pressure switch; and when all 5V sensors where stuck with .7V for quite some time.

Good that you have a replacement PCM, and bad that you will need to get the PATS keys programmed into the new PCM. If for some reason your new (used) PCM does not fix the IMRC, you will be back in the other thoughts-> WHAT external sensor or PCM sub-system is causing the PCM to make the IMRC act like that and WHY are there no DTC's?

BTW there is a DIY PATS key programming method, if you are interested, and if you are able to use a laptop & the OBDII Port, on your car, and Forscan tolerant.

Mobile locksmith is another option, call around for quotes. Or, drive you car to Ford with the PCM and have them do the programming, call in advance for price quote.

BTW, did you ever try the original IMRC Module AFTER the 5V power problem was fixed?

[email protected] 05-01-2019 09:40 PM

Yes, I did try the original IMRC Module after the Vref voltage was fixed and it worked the same as with the two other new IMRC Modules I have.

Dropped the car off at the local Ford dealer after their service department closed for the night and replaced the PCM with the new used one I have to save paying them $80 to do that. They agreed to take my non-starting car into their shop in the morning and reprogram my PCM for $150. If it works great, if it doesn't I will put my old PCM in and drive the car till I replace it in the next year or so. Have also been watching Copart.com for a deal on a 2015 or newer Focus.

Wish me luck.

[email protected] 05-04-2019 10:14 PM

Well the dealer was unable to reprogram my used, like new looking PCM, with identical numbers as my original except for the last two digits of the serial number. They offered to sell me a new one for $1,230. So i paid the $152 for their failed attempt and drove home with my old PCM. The car still runs great, has no diagnostic codes but get 20% less fuel economy due to the intake manifold runner flaps being open all the time.

So I found a 36,000 mile 2015 Focus SE on Copart for $5153 and bought it. Will try to drive it back to Kenosha, Wisconsin from Detroit, Michigan on Monday. The plan is to sell my 2010 Focus SEL for $1,000 after we see if the Copart one is at all reliable.

Thanks for all who helped work through my IMRC issues especially Marde and Paul.

Mike


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