[judedude]

98 1.8t 70k. Driving home car stumbled and got flashing CEL. Hooked up Vag-Com and got codes 16684 & 16686. I had the car towed to my house. I am pretty sure it is either a coil pack or the ICM. How can I determine which it is. Cylinder 2 is always misfiring then I get the random misfire code. Can I switch coil packs and see if it misfires in the exchanged cylinder? I need to determine which part to order and get back on the road. The 90 Comanche doesn't cut it for work.

 

[Boris]

Switch the coils and see if it's still the #2. Then you know it's the ICM (which I bet it is). If the misfire is on another cylinder then it's the coil.

You can get the ICM HERE for fair price.

 

[dronek75]

98 1.8t 70k. Driving home car stumbled and got flashing CEL. Hooked up Vag-Com and got codes 16684 & 16686. I had the car towed to my house. I am pretty sure it is either a coil pack or the ICM. How can I determine which it is. Cylinder 2 is always misfiring then I get the random misfire code. Can I switch coil packs and see if it misfires in the exchanged cylinder? I need to determine which part to order and get back on the road. The 90 Comanche doesn't cut it for work.

yep i had the same problem couple months ago...misfiring on cylinder # 2 ....it was the Ignition Control Module

 

[Kenny Payne]

Here's a good writeup on verifying ICM failure: http://www.clubb5.com/forums/viewtopic.php?t=66779

Kenny

 

[judedude]

Thanks for the help. I ordered the ICM at the site you recommended. Hopefully this will solve the problem. I exchanged the coilpacks and still got misfires on the same cylinder.

 

[l5gcw0b]

When were your plugs last changed? Fresh plugs cleared up my random misfires.

 

[AceConrad]

Could also be the throttle body needs cleaning. My 98 has done the stumbling misfiring thing twice and cleaning the throttle body cleared it up both times.

 

[judedude]

It was the ICM. Had it Red Labeled from Busdepot. Installed and back on the street. Thanks for all your help.