DIY Ignition Control Module (ICM) Replacement. Lots of Pics!

**beeza** · 18-04-2010 04:36 PM

Oh sweet,too easy!

**grifty** · 18-04-2010 04:41 PM

it was much easier than i though it would be, if u have a pen and paper and make note of where everything goes then u cant go wrong!

**beeza** · 18-04-2010 05:09 PM

Too easy!!

**specialst** · 19-04-2010 03:46 PM

Im glad it worked out for you grifty - many other fellow honda owners will start needing to replace their ICM's purely due to age.

Fortunately I was able to do it all on the car and didnt need to remove the dizzy.

Out of curiosity - Did u remove the dizzy due to engine bay space being an issue?

**specialst** · 19-04-2010 03:53 PM

Also folks. I forgot to mention that if you cannot see the rotor screw behind the dizzy - its because the motor + pistons arnt in the "correct position" (I dunno if its TDC or what but...)

Simply replace and screw on the rotor cap and briefly crank the engine by turning the ignition key. This will change the rotors position (BYM's way lol). Repeat until you can see the rotor screw (rotor will be in the identical position as the photos).

Added to the original article.

**grifty** · 20-04-2010 05:27 PM

Originally Posted by specialst

Im glad it worked out for you grifty - many other fellow honda owners will start needing to replace their ICM's purely due to age.

Fortunately I was able to do it all on the car and didnt need to remove the dizzy.

Out of curiosity - Did u remove the dizzy due to engine bay space being an issue?

i had to remove the dizzy because the bolts holding in the ICM heatsink were outside on the bottom of the dizzy, if they werent done up that friggin tight i could of taken out the ICM without removing the dizzy.

**saad** · 17-08-2010 12:34 PM

Hey grifty what do you mean you used a permanent marker? I replaced mind but it didnt fix the porblem, but the ICM supplied was wrong as it didnt have the 3 mounting holes. Ive ordered a new one, but to me it seems weird that fter replacing the ICM, even with a wrong one, I have the exact same problem

**grifty** · 17-08-2010 12:39 PM

Originally Posted by saad

Hey grifty what do you mean you used a permanent marker? I replaced mind but it didnt fix the porblem, but the ICM supplied was wrong as it didnt have the 3 mounting holes. Ive ordered a new one, but to me it seems weird that fter replacing the ICM, even with a wrong one, I have the exact same problem

well the dizzy can be moved to either side to advance or retard the timing. I did not want to screw up my timing settings so i just marked where the dizzy's position was in relation to the head so when i removed it i knew where to put it back after i had finished working on it. ill get some pics for u in a min.

**grifty** · 17-08-2010 12:44 PM

here you go

the green lines are the marks i made

**saad** · 17-08-2010 12:55 PM

Oh damn, didnt know that changing the distributor position side to side changes the timing! Damn! I somehow need to get the timing fixed now...

Also is it possible that the tacho feed wire is just loose, so when we hit high rpms, the tacho signal is not being sent, causing it to go crazy

**grifty** · 17-08-2010 01:02 PM

Originally Posted by saad

Oh damn, didnt know that changing the distributor position side to side changes the timing! Damn! I somehow need to get the timing fixed now...

Also is it possible that the tacho feed wire is just loose, so when we hit high rpms, the tacho signal is not being sent, causing it to go crazy

i dont think the tacho signal could be loose, if it wasnt connected then you wouldnt get any rpms on your cluster. I think your best bet is to try and possibly borrow an aftermarket tacho and see if it does the same thing.

have a look on your dizzy if u can see the markings of where the bolt used to sit before you removed it, if so then just move it back untill they all line up.

**mooshie** · 22-01-2011 10:20 AM

Anyone know what ICMs are compatible across Honda engines? My B18C is hesitating when it is hot and on a light throttle load and I have a spare Concerto distributor (it was on my wreck DA9!) which I know is working and I have removed the ICM.

In the service manual the B18C and the B18B have the same distributors but when I looked up parts on the Supercheap website they have a different ICM part number listed for the C and B? the B18B has the same part number as the D16A8, D15Z1, D16Y1, B18A and costs around $70-$110 but the B18C part is over $250!

So can I just use the Concerto ICM? will it screw anything up if I just test it? Visually it looks like it will fit, although I haven't taken out the ICM in the B18C yet.

I am going to post this in the Technical section as well just in case people who are 'in the know' dont check how to do things they are already experienced with!

BTW a loose connection on the ICM will cause a crazy tacho, I had to fix mine on the DA6 recently, simply pulled off all the connectors, tightened them with some pliers and put them back on, voila! no more bouncing tach and the car runs smoother too.