Took it to a shop in town Saturday. They could do nothing and referred me to the dealer. They say its a loss of communication to the computer. They didn't think it was a bad ground. What do you think? If its the computer, is it an easy change and what else should I change along with it?

 

Loss of communication can be as simple as a loose wire in the wiring harness connection, a burnt ground wire , a result of a loose ground.
It could also be a dying battery or a dead cell in the battery.
Try a lobotomy, remove the battery ground cable at the battery for at least 30 minutes, whilst it's disconnected check the ground cables in the spare tire well and under the hood.
Check the fuse box under the hood are the two wires tight n the left of it , is the red single wire tight, that's the wire going to the EPS motor.
Check to confirm the fuse box halves are tight.
Check to confirm the ECM and TCM connections are tight.
Check all of the fuses and relays are pushed in firmly.
Have a cold drink or cup of coffee!
Now reconnect the negative cable at the battery.
Start the HHR .
If the problem still exists then off to your dealer, as suggested in last post

 

I had virtually the same thing happen to me last weekend (also '10 LT), I didn't see all the messages cause I was too busy trying to find a safe place to stop. But spedo would rapidly drop to zero then back up to speed over & over: I saw the "service traction control message: & at least 2 other messages that I didn't see enough to read. PS never went out, but gas pedal was partly non-responsive, as in: I would step on gas & sometimes it accelerated & sometimes it didn't.


At the time, I thought maybe it was because I didn't let my OBDII reader sync with my phone before taking off. As soon as I found a safe stopping place (about 1/4 mile after I started out) I shut her down, unplugged the OBDII reader & started on my way again without anymore problems. I've put 88 miles since then & no more issues, & the reader never did send anything to my phone, but I know the reader still works cause I checked it on my Hyundai Accent & still getting codes from the Accent.


I hope it never happens again, but at least with this thread, I have a starting point if it does happen again.

 

Did anybody bother reading post #2? Do you suppose a loose fuse box connection could cause a "failure to communicate"?

I think I'll go eat some hard boiled eggs.

 

chaosdsm - You might consider checking a few of the items that have been suggested NOW, rather than wait for the incident to occur down the road. At the very least it will isolate some of the possibilities. If it comes back, you might not be so lucky to have a safe stopping place.

 

nobody got the reference in 1.25 hours?

 

I hope you let those eggs "cool"

 

I had an issue where the check engine light would come on and the DIC would display "SERVICE ESC" SERVICE TRACTION" and "REDUCED ENGINE POWER" and it ended up being a dirty throttle body that was causing it. I also had the gauges go haywire when the battery was virtually dead. Your issue is likely not caused by either of these things, but you should consider that whatever is causing the issue might not be obvious.

 

Not happy after taking it to CHEVY dealer. They said it was a bad ECM, replaced it and problem showed back up on way home. Will update later, I just don't have to time to do this myself.

 

"Not happy after taking it to CHEVY dealer. They said it was a bad ECM, replaced it and problem showed back up on way home." - well go straight back and raise $hit!!!!