Just a question on a ignition control module? On a 2007 hhr 2.2 were is this located at? valve cover or front of engine ,for the love of it i cannot find it.. I look up this part and there is one for my vehicle but were? lol

 

Under the Darth Vader hood in front of the fuse box. It is the ECM/PCM, no real "ignition control module".

 

Some people call the spark plug coil ignition modules. Don is correct that the hhr built the ignition module into the PCM.
The ignition modules that you see in part stores are for other ecotec engines for other gm models.
Sometimes the aftermarket parts books jumble things together.

 

Man i feel dumb but you look up this part and they show it, so i am like ok i know there is coils for every cylinder and the a pcm that controls the spark . so were does this part play in ... lol learn something new every day....

 

I have done some more research on this and I'm going to amend my earlier post. It appears that the early production 2006 hhr did use a coil pack and a separate ignition module. It was changed to the system we have now in a mid year change in 2006.

I learned something new today also

 

Here's the ign contr module on my girlfriend's 2006. I'm about to replace just the Ign contr module. Getting low rpm miss, but seems to run fine at normal highway and cruising rpm unless under load, then more misfire! Is either the coil pack or the Ign contr module. I'm about to measure resistance across all coils to see if all the same or not, if all same, then replacing Ign control module. Dealer troubleshoot cost cost more than the part!
Here are images of top of engine where ign contr module is sitting on valve cover, as well as with coilpacks and ign contr mod removed from engine...
Ign cont mod is the little silver rectangle set inside the black coil pack... Coils are not interchangeable on this one as they are on others (guessing from other years)...
Good luck!

 

That in not the likely problem! Does coolant seem to disappear? Have you performed a compression and leakdown test?

There is a link in my sig on how to add pics to a post.

 

x2 what Donbrew stated above.

There are numerous other things that cause your "misfires" - and the ignition system seems to be the least common cause. So you are likely just throwing $'s at it.

What CEL error codes are you getting?

ps: you didn't state what engine you are dealing with - but I gather it is a 2.2, which came with an all-in-one coil pack, vrs the 2.4L that came with individual coil packs for each cylinder)