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HOW TO: IMRC Removal and Repair

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dsi imrc
231K views 191 replies 86 participants last post by  AussieRigby 
#1 ·
First off, credit for this idea goes to an older thread which now seems to be gone. I'm just going into slightly more detail.


This problem is very common, and I suspect 80% of SVT owners need not replace the IMRC but simply clean the internal contacts.


So, do you have this problem? If you answer "no" to the following, it is 90% likely this procedure will work for you:

1) Is my cable broken?
2) Is my lever broken?

What you need:

1/4in ratchet with 8mm & 10mm sockets
Phillips screw driver #1 & #2
Soldering Iron
Thermal paste
RTV



Ok, lets begin.


First, remove the drivers side headlamp, battery, battery tray, and airbox/uper half of CAI/SRI:






You see that the IMRC is located behind the headlamp.

Now, before unbolting the IMRC box, disconnect the cable from the lever. This is done by (with one hand) roatating the lever towards you, while grasping the end of the cable and sliding it off of the post.







Now, unbolt the box and remove it while snaking the cable out along the path shown.



Ok, the hard part is done [thumb]

Next, take the IMRC to your bench to begin disassembly.



First, remove screws securing cover. Then using a straight razor blade cut around the seam to free the RTV.



Now that the unit is open, remove the screws as shown, and desolder the power wires and connector pins.



Remove PCB, and this is what you have.






At this point you will notice, there is not much to this box. Notice the gears are made of metal, thus the odds they will ever strip is very slim. The electrical circuit is very simple as well, and failure of these components under normal operation is slim to none. The motor is nothing more than a glorified coil, and under normal operation coils are basically indestructable.

Leaving us with the true weak point of this unit... the contact [smackbum] Which is the copper strip with a nickel plated contact shown in the above picture.

Now, to remedy the dreaded P1518, we must burnish (clean) said contact.

Notice the grey color. This is not very condusive to conduction. [idea]






Using a piece of fine grit sand paper (paper), or a fine nail file (file), press down gently on the copper strip (DO NOT BEND COPPER STRIP),

Insert paper/file, release copper strip and pull paper/file out. DO NOT MOVE BACK AND FORTH, SIMPLY PULL.

Repeat 3-5 times, and marvel at your new looking contact.




Now, before you reasemble the box, make sure your FET has enough remaining thermal grease to dissapate heat properly... In my case, I wiped it away and used thermally conductive gap pad.

Add thermal grease if you need to.








Now reattach the PCB the reverse of removal.

Using standard RTV, run a bead around the edge and screw the cover back on.




Bolt up the box to its bracket and run the cable along the same path you took it out of. BE SURE TO RUN THE CABLE INTO THE GROOVE BEHIND THE BATTERY TRAY, SO THAT WHEN YOU PUT THE TRAY BACK IN YOU DO NOT SMASH THE CABLE.

Hook up the cable end to the lever post by rotating the lever towards you and sliding the groove of the cable end on to the post.

Replace airbox/upper half CAI/SRI, battery tray, and battery.

Hook up battery... Start car... and enjoy your engine codeless dash [wiggle]

I'm sure I forgot something, I will edit as I remember things or get suggestions from other members.
 
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#101 ·
I decided to finally fix mine today. Had it out and took the cover off. I have the cracked solder joints so I go looking for my solder iron. After searching for 2 hours I gave up and put the intake and battery back in. I guess I'll take the module with me to work Monday and get it finished. I'll just take it apart again next weekend.
I may also take that weight off of the trans. linkage while I'm in there and see how that feels.
 
#102 ·
Ok so my SVTf runs like ass some days and runs great other days. I have 139k on mine, and I was wondering if this could be the issue? No cel, but I believe I did get the code once last month, but it went away. Some days I have great torque, and other days I have nothing. I work at Oreilly auto parts, so the imrc is cheaper for me. Would it be worth replacing? I can't solder or I would try and take a look.
 
#103 ·
Seems most likely to be it. I would still take it apart and look around its not to hard at all to do. You can always find a friend to solder for you. Also big thing is the copper contact point can be dirty and be making it run funny. Be yes I would replace it if not taking apart lol.[;)]
 
#104 ·
have a p1518 code pop up today..car still runs perfect no change in idle or power, also i cant where to get the imrc module(the box?). what is the dsi clip? and the scanner says nothing but p1518. i see many different explanations for it but im not sure how the component works so anyone who can explain it? thanks!

03 focus svt..stock
 
#107 ·
Focus SVT IMRC

This is a great post
My SVT was getting the dreaded IMRC check engine light when I found this post
Figured I would try to fix my module today after I retuned from the salvage yard.
I found a unique thing today I think
While I was walking around I found a duratec 24 valve engine in and decided to look inside the IMRC Module The 99 and new have the short cable.
Took the screws loose fo the circuit board Wiggled the connector and the circuit board and the motor are easily removed.
Turned the gear with the cable on it and the cable slid out. It even had the same number on the box as my 02 foocus SVT. YOu can clean the contact and whatever else you need to do and dont have to unsolder anything.
ALSO found out a 96 Contour duratec 24 valve V6 engines module is a dirct replacemnt for the SVT. Just put one in mine and cleared the light
WORKS GREAT...
 
#108 ·
Got a P1518 at 108K miles a few months ago when winter hit. Cleared it immediately - never had a driveability symptom so it was obviously an intermittent problem...until recently when it would come back within days... Saw the thread and decided to actually try and fix it instead of buying a new module.

It was pretty easy - thankfully I had a sharp soldering iron to keep hot spots small and it was interesting getting the holes in the IC board free from solder so I could align the connector pins... a little patience was the key.

48 hours later still no code. Thanks for the good writeup
 
#111 ·
Thanks for the great write up. Had the cel popping up till it came on all the time. Pulled the imrc today, didn't desoder anything just took screws out and used a screwdriver and sand paper to get between the contacts. Didn't get to test drive it yet but when I started it the manifold was pulled closed and the cel was off. Hopefully stays off for a good while.
 
#112 ·
My fix did not work. I did this back in Nov. resoldered the joints, cleaned the contacts and put everything back. got the CEL within a day. I'm getting ready to get a used one from a pull a part to see if it really fixes it before I try a new one. I hear that several other models use the same box with different cable legnths that will swap right in. I know of a couple of guys who installed a new IMRC to only have the code come right back.
mine pulls the lever at start up then releases after a few seconds. then the code comes right back if I reset it.
 
#113 ·
ok, I can verify that a IMRC from a cougar (99-02) is the same as the focus. The cable is slightly longer (2 to 3 inches). I just put one on mine and it has fixed my issues. The old IMRC actuated the lever slowly then snapped back to the long runner position after starting and I think this was the whole problem. Probably a timing issue in the activation of the IMRC circuit. The replacement box actuates much quicker and holds there just like it's supposed to. Taking off is so much better with the added touque on the low end now.
 
#117 ·
Mine is good to go now. my gas mileage has also picked up some too.
 
#120 ·
Changed my imrc today and it made a difference. Only problem I encountered was trying to remove the air box, Make sure to just pull really hard straight. I thought it was bolted. Also getting the old cable off the plastic, I just got some pliers and broke the tabs. Gas milage is up. Thanks for write up!
 
#121 · (Edited)
hey guys, I want to add a little info to this thread to save some headaches for the next person who has to do it. This is to show you how to figure out what is wrong with your IMRC once you open it up.

1. rotate the gears so the cable is pulled in.

2. Measure the circled points with a multimeter or ohm meter for resistance.



A. IF they measure 0ohms, relax! you do NOT have to desolder the pcb and remove it. The contact is not corroded to the point that it increases resistance. Your problem is elsewhere. Go to step 3.

B. IF they do not give a measure, the circuit is broken and there is no contact between the two points. Go to step 3.

C. IF they measure in excess of 0ohms, the connection needs to be cleaned to make a good connection. Desolder the 6 pin connector, remove the PCB from the box, and clean the contact as shown in post #1. Now test the points again. Should be 0ohms. Now, once this is done, it does not necessarily rule out further issues. You may need to continue to step 3 still.

3. You're issue is not the contact on the reverse side of the PCB! Good news, you do not have to desolder and remove the PCB. However, you have an issue with a circuit on the board, most likely a cold solder joint. Use your multimeter to measure resistance between points in line. They should have zero ohms of resistance unless they are going through a resistor. In my case, I had 5 cold solder joints that showed no connection at all. Pictured below are the joints that were bad on mine:



The 2 points on the 331 resistor as well as the 3 points on the black chip that resistor goes to were all bad connections. Everything else checked out fine. I do not know if this will be a trend, or if the cold solder joints will be random, but it seems coincidental that all 5 bad points are essentially in the same circuit of the board, so I would check them first to rule them out. Reflow the solder and retest for resistance. Should have zero ohms if you follow the circuit correctly.

hope this helps!
 
#122 ·
just want to say thank for this thread my imrc cable got some battry acid dripped on it where it runs under battery box and was split in two didnt know my car running so poorly though until the imrc box started making a grinding noise every time i drove it thought my car lost power because we moved to 8k ft above sea levelhttp://www.focusfanatics.com/forum/images/smilies/icon_smile_duh.gif lol
 
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