I need some help on how to check a 2006 Chevy HHR. I have checked all my fuses and I do not have power to fuses number 42,43 and 45. The fuses are good. I was told that I may need a computer. The started first not being able to silence the alarm by inserting key in ignition. Then my HHR would start but would start missing - out. Sometimes while driving I would hear a
clicking from the shifter area then doors would lock by themselves then all the
gauges would flicker then after a while return to normal. I also have no power
to diagnostic receptacle where a scanner is plugged in. Any help would be appreciated thank you.

 

First things first.
How's the battery voltage? Needs at least 12.4 volts to be considered charged. Even then you could have a battery going bad. You should take it and have it tested to make sure.
From your description, it sounds like a battery problem. Other possibility would be a loose or corroded connection in the battery main power feed.
The "no power" to the OBD receptacle is usually because there is no power at the cig. or power oulet.(it's the same fuse that powers the OBD port)
Check that fuse( #29 under the hood I think)

 

I noticed you've had a few other posts on here regarding things such as no power to the aux. power outlet, problems with the dash lights etc.
You never followed up with any results on those after the good members here gave you some advice.
If you want some help with your current problem it would help us to know what was done about the other issues.

A little courtesy goes a long ways.

 

I agree with firemangeorge on all of the above. Fuse 42,43 and 45 are trans,engine and injector modules. Makes me think about a fuse link that may be blown or a problem in the PDC. ( under hood fuse box)

 

Pleaes forgive me for not following through on my previous posts. The information provided help me to fix the problems thank you.

 

Please Keep us updated on how things go The more info we have the more advise we can give. Also your updates may help others with a problem in the future.