View Full Version : Icm ?

04-16-2005, 05:43 PM
Alright, I've been having some recuring problems with a misfire in cylinder one. It seemed to happen once in a while then go away. So I changed the plugs thinking that might be the problem. Get about 40 minutes into the new plugs and its missfiring again in cylinder one. Then it goes away and drives fine. Today I got in the car drove for like 15 miles and it ran like a champ. I stop and throw in some gas, As i pull out of the gas station it starts to hesitate and the cel starts flashing.. give it a minute and it still is shaking and hesitating and flashing the cel. i limp back to school thinking i have a bad coil pack. Getting back to School I search on here and see the Icm going on pre 00 b5's more so than coil packs. So its time to do some trouble shooting. I go out side and replace what i believe to be cylinder one coil(closest to the belts and bumper) with the second coil pack. Start the car and same thing hesitating. So now do i have to replace the ICM? I Noticed earlier that the icm would tick every now and then... do you think that has something to do with it? Just so you know its a 99.5 and it already has a Huco brand ICM

04-17-2005, 07:41 AM
That's pretty much the extent of trouble shooting I'd do too. Sounds like the ICM, unless for some strange reason you have bad wiring to that coil or something. I assume you have a scan tool or something to tell you that it is still hole #1 missing when you swapped the coils. That ticking you heard was probably the evap purge valve solenoid, it's right there too.

EC Motorwerks
04-17-2005, 08:15 AM
Sounds like an ICM. I have one in box never opened if you need one. PM or e-mail me for price.

04-17-2005, 10:21 AM
pm sent

thanks guys

04-17-2005, 10:25 AM
theres a write-up to test the ICM on AW> might wanna try that before going on a buying a new one

04-17-2005, 02:49 PM
Would be nice to know for sure... But it sounds like an intermittent problem so the results might be misleading. If it turns out bad you know it's bad. But if it was good it could still be bad......

04-20-2005, 10:38 AM
well it tested fine, now what?

04-20-2005, 11:14 AM
swap packs, clear the codes and see if the misfire follows the pack. Wouldn't hurt to clean up the mounting surface for the icm and put some new heat sink compound on there. $1 at radioshack

04-20-2005, 11:28 AM
Switched all the packs, i'm going to go out later and test to see if i'm getting spark at the cylinder.... i pulled the plug and its black as night. oh and another question is there any way to test the wireing to the icm?
thanks, dan

04-20-2005, 11:51 AM
isn't the aw icm test testing the wiring?

04-20-2005, 12:00 PM
it tests the resistance between the icm, which sees if there is any discrepancy(sp) between the four plugs. mine all tested equal, i want to know if there is a way to test the wires going into the icm not the icm itself

04-21-2005, 01:44 PM
bumb and update...

I put new plugs into since the ones that I put in less than 100 miles ago are already fouled and black. I started the car and still have a missfire. ANYONE have ideas, i'm grasping at straws right now and don't have the time or money to send it to a shop. ps anyone in the rochester area with a vagcom?

04-26-2005, 02:39 PM
just thought i'd post the solution to my problem incase this happens to anyone in the future....

Upon trying everything even a donor icu swap I was at a loss. I figured it had to be something with the wires. I took my multimeter and tested resistance on the 5 pin plug going into the icm. The plugs marked one and two measured ~.5 plug 3 read 0 (ground), plug 4 was ~.5 then plug five registered nothing complete resistance. DUN DUN DUN. turns out the signal wire for cylinder one had gotten to hot next to the down pipe and had melted/broken I put on a new wire in and misfire gone....

Ride on,


04-26-2005, 05:14 PM
Nice. Good work.

04-26-2005, 05:19 PM
dude, sorry about the non response. The post disappeared and i have zero short term memory

04-26-2005, 06:45 PM
haha no problem bitter i hold no grudges