Every couple of days, my HHRs gauges will all go up and down several times, the security light comes on, sometimes the check engine light will come on, and I get a power steering warning too. This lasts for a few minutes and then usually quits. Sometimes while its doing this it will shift really hard too and it feels like it has no power. Anybody know what would be causing this?

 

Welcome to the site, have your battery load tested at your local parts palace, anything under 12.4 volts is considered a dead battery.
how old is the battery, doesn’t much matter, it’s the charge and the cold cranking amps.

 

Okay I will do that..i am not sure how old the battery is. I bought the car in March of this year. thanks!

 

Let us know the outcome of the test

 

Okay I will! My trunk hatch also stopped working. Could that have something do to with the battery too or is that a separate problem?

 

It's a possibility. Does it not work at all or only when the gauges malfunction ?
The bad part is the battery is in the back and to get to it you have to lift the rear hatch (lift gate)
It can be manually opened but that means going in from the back seat .
Do you have an owners manual ? If so look in the index for Manual Liftgate Release.

 

And once you get it opened, put a folded towel over the latch to prevent it closing in the opps moment when you instinctively close the hatch!

 

I went to AutoZone and they said my battery and alternator are good. He pulled the check engine codes that were saved and this is what he came up with. He said to check the grounds and if that didnt work I need an engine control module. My trunk latch doesnt work at all, but he was able to show me how to do it manually from the inside. Any advice or tips on checking the grounds?

 

ECM's (Engine Control Modules) very rarely go bad.
Your talking to a Auto Zone employee.
The code U0073 I think should be looked at.
I'm sure Don will chime in on this one.
It would be interesting to know how many times (called a count) each fault code happened.
Are you the original owner ?
How many miles on the car ?

 

I see you have a 2008. Is it an LS, LT ?
How many miles on it ?
Are you the original owner ?
The reason I ask is because the first code looks to be a possible bad thermostat. (Could have been fixed already) and the code was never erased.
Then the next two looks to have a transmission related problem.
And the last one leans towards an ECM communication problem.
Were all codes erased at Auto Zone ?
If so, when the check engine light comes on again have the codes read again.