Icm-icrm

kenewagner

Registered User
Can someone break down the functions of the ICM and the ICRM? It would be nice to have a picture of location as well as what each does. My limited knowledge of the two is the ICM deals with ignition and the ICRM has a lot to do with the the radiator fan. Would like some imput on their function and whether they could be contributeing to my wiring grimlins

Ken
 
Not sure about the ICM.. but the IRCM is located behind the passenger side headlight - it's a small black box. I think you might haveta pull off the cover panel on that side?

-Melon
 
My manual shows the ICM but I cant even find a refrence to a IRCM. I was hopeing some of the more knowlegegable guys would chime in and describe their function and why or how they can affect HP power. I did a search and there doesnt seem to be much information. I have not touched the car since I got back, but am lining up some replacement parts

Ken
 
The IRCM (Integrated Relay Control Module) basically has one function on the early model SC's, and that is to control the operation of the low/high-speed cooling fan. On the later models, it also has another internal relay circuit that triggers electrical power to the fuel pump when the ignition is switched on. Other than that, it shouldn't have any real impact on performance. (I guess if you have no power to the fuel pump, you don't have much in the way of performance....) I'm not familiar with the term "ICM", is that another designation for the "DIS" or maybe the "EEC"?
 
Whoa, there is one other small function on the IRCM that is not at all well documented and can indeed cause a severe hair falling out problem. there is a transister circuit that supplies reference voltage to many of the sensors, Like MAF, TPS and others. ScrapSC and I spent many long hours chasing gremlins and since replacing the IRCM we were able to make the shootout where he was able to win MOD3 car now runs like it should have been doing..............Dan
 
The IRCM (Integrated Relay Control Module) basically has one function on the early model SC's, and that is to control the operation of the low/high-speed cooling fan. On the later models, it also has another internal relay circuit that triggers electrical power to the fuel pump when the ignition is switched on. Other than that, it shouldn't have any real impact on performance. (I guess if you have no power to the fuel pump, you don't have much in the way of performance....) I'm not familiar with the term "ICM", is that another designation for the "DIS" or maybe the "EEC"?

IRCM module from my understanding does control the fan like you say. Mine is a 93 so would that be a later model? My manual said the ICM is an Ignition control module. It is located off a small bracket attached to the upper radiator support, looks like a heat sink with a plug in it. This is all according to the Ford Manual. It has been suggested by knowledgeable people that my HP problems are electrical. So I am looking to replace the eec and the IRCM. But I dont see the reasoning behind IRCM being a logical sort of guy. I dont know anything really about the Ignition control module but it sounds like more of a factor than the IRCM. Just trying to expand my horizons here

Ken
 
no help Ken

Whoa, there is one other small function on the IRCM that is not at all well documented and can indeed cause a severe hair falling out problem. there is a transister circuit that supplies reference voltage to many of the sensors, Like MAF, TPS and others. ScrapSC and I spent many long hours chasing gremlins and since replacing the IRCM we were able to make the shootout where he was able to win MOD3 car now runs like it should have been doing..............Dan

Also the A/C compressor clutch. The fan works, Freon in the system & the compressor never kicked on.....replaced the IRCM & that fixed it. this reply was to help the next guy on his search for the module.
 
Whoa, there is one other small function on the IRCM that is not at all well documented and can indeed cause a severe hair falling out problem. there is a transister circuit that supplies reference voltage to many of the sensors, Like MAF, TPS and others. ScrapSC and I spent many long hours chasing gremlins and since replacing the IRCM we were able to make the shootout where he was able to win MOD3 car now runs like it should have been doing..............Dan

When you get into the 50s loosing hair is not a good option. I had heard that it does provide power for other sensors but couldnt find someone who was actually experencing the problem. Do you feel that was the problem or just contributed to the problem. I was told to replace the eec as well. Did you guys replace it as well?

Ken
 
Did You try looking at the IRCM diagram in the " FAQ Forum "

I looked at the diagram but electrical diagrams dont click well with me. I know of others that have struggled with producing HP like myself and cant seem to make the HP their Mods should make. My car has never dynoed well and the problem needs to be addressed before throwing more modifacations at it. For me I like to know why something doesnt work, how to fix it, and why the fix worked.

Ken
 
Ken, it was Anthony (ScrapSC) and Dan (old_coot) who both recommended this to me while you were struggling on the dyno. Anthony went through a lot of trouble trying to find his gremlins.

We really need name tags with both screen names and real names.

Michael
 
Ken, it was Anthony (ScrapSC) and Dan (old_coot) who both recommended this to me while you were struggling on the dyno. Anthony went through a lot of trouble trying to find his gremlins.

We really need name tags with both screen names and real names.

Michael

I talked to both you guys at the dyno tune but like Michael said didnt put the screen name to the face. I know you talked about the dash and harness replacement. Do you think it was the actual ICRM that made the diffrence? After replacement of the module was there a noticeable improvement or change

Ken
 
'89 thru '91 IRCM contains the following relays:

EEC PWR
LOW SPEED FAN
HIGH SPEED FAN
A/C

There are signals FROM EEC to tell the specific relays when to do what, but there is nothing from it to operate any sensor inputs.

I'm looking for a '93 & up now to see what's different.
 
Just so I know what I am talking about, I snapped a picture of a module in front of the air box. Is this the infamous IRCM module that replacing will free up my missing 100 ponies?

Ken
 

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Yes Ken that is it and there was an immediate change in the car after it was changed--up until then it didn't seem to make any difference what we did. Also at the same time we unplugged the knock sensor---just behind the passenger side motor mount, on the block not the low oil sensor in the pan---the guys on the Buick forum have found that some of those sensors are sensitive to the noise roller lifters make --that little critter can pull eight degrees of timing out no matter what is commanded...As best as we can figure since that circuit powers most of the sensors we went through lots and lots of parts that kept giving bad indications until we changed it then everything was good except the TPS and you see the results from the shootout---that is the first time the car has done anything right and now it seems just fine---sooooooooo for what its worth I recommend changing it first before the computer and DIS and MAF---its the common denominator...............Dan
 
Yes Ken that is it and there was an immediate change in the car after it was changed--up until then it didn't seem to make any difference what we did. Also at the same time we unplugged the knock sensor---just behind the passenger side motor mount, on the block not the low oil sensor in the pan---the guys on the Buick forum have found that some of those sensors are sensitive to the noise roller lifters make --that little critter can pull eight degrees of timing out no matter what is commanded...As best as we can figure since that circuit powers most of the sensors we went through lots and lots of parts that kept giving bad indications until we changed it then everything was good except the TPS and you see the results from the shootout---that is the first time the car has done anything right and now it seems just fine---sooooooooo for what its worth I recommend changing it first before the computer and DIS and MAF---its the common denominator...............Dan

At the shootout I replaced the electronics on the Maf per Daves suggestion. My power just drops at 4000 rpm. I ran fairly hard later in the day and had no problems. My 1/4 mile times seem to be in line with a 275-290 HP engine. I dont beleive the Maf picked up all those extra ponies. The Maf was inexpensive so I didnt break the bank. I feel like I have had a problem even early on when I was modding the engine, getting the HP that everyone else was getting. I am wondering now if there are more guys out there discourgaged with low numbers that are a simple swap from making good numbers, even on fairly stock engines. Some of the stock and super stock engines are pulling more than mine is now. I beleive I have located all the parts. I will post the results. Im glad there was a noticable diffrence when you swapped the module, thats what Im looking for. Than back to the dyno for numbers.

Ken

Ken
 
Yes Ken that is it and there was an immediate change in the car after it was changed--up until then it didn't seem to make any difference what we did. Also at the same time we unplugged the knock sensor---just behind the passenger side motor mount, on the block not the low oil sensor in the pan---the guys on the Buick forum have found that some of those sensors are sensitive to the noise roller lifters make --that little critter can pull eight degrees of timing out no matter what is commanded...As best as we can figure since that circuit powers most of the sensors we went through lots and lots of parts that kept giving bad indications until we changed it then everything was good except the TPS and you see the results from the shootout---that is the first time the car has done anything right and now it seems just fine---sooooooooo for what its worth I recommend changing it first before the computer and DIS and MAF---its the common denominator...............Dan



Knock sensor hmmmmmmmmmmmm... I replaced mine when i did my rebuild because i accidently broke the old one! Power has just not been the same and i cant figure out why.. I really wonder now if this could have somthing to do with it? (not to hijack the original thread) but it makes me wonder.. Will the car run fine with the sensor unplugged??
 
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