09-05-2012, 02:41 PM
Official GM Rep
Join Date: Mar 2010
Location: Global Headquarters in Detroit, MI
Originally Posted by djrobnyc
I'm looking for some help in diagnosing an intermittent (but potentially dangerous) problem that I've had with my 2010 Impala that has about 40,000 miles and the 3.5L engine (it's an LT).
About two months ago as I was driving on a local highway -- about 55-60 -- I felt a slight hitch and the Service Stabilitrak lamp/message lit up. I continued to drive another mile or so at this speed - and then the Starting Disabled Service Throttle and Engine Power Reduced messages came on, as well as the Service Engine Soon lamp. The car slowly shut off -- but I made it to the side of the road. The car would not restart for 2 minutes - I was then able to restart it and it drove okay, but I pulled over to a safer part of the road, called GM and they had the car towed to the dealer where I purchased it from.
The shop told me the car spit out a Throttle Body code and that part was replaced. They kept the car for two days to test it and the problem seemed to have gone away.
Unfortunately, that was not the case. This same thing happened the other day. Everything happened exactly the same. However, this time - after I got the car started after 2-3 minutes -- I drove it to work, which was a few miles away. At the end of my work day, the car started up fine and the Service Engine Soon lamp was NOT lit. I drove the car back to my dealer - and they have it now.
This time, they tell me the car spit out a Low Voltage code - which they traced to the battery. They tested the battery, it failed that test so they've replaced it. Again, they have kept the car for two days for further testing - and called GM to tell them about the problem. I questioned the shop as to whether this was really the problem part (the battery);they seem to think it is.
While I appreciate the effort by the dealer - I do feel they are really trying to find out what's wrong - I'm a bit skeptical.
Can anyone out there help? It's not fun to try and have to navigate getting to the shoulder of a highway while going 60 mph to 0. And my wife won't get near the car now...
The only other piece of evidence I can offer is that both times this happened there was less than a quarter tank of gas in the car.
By the way, I've read on some other sites of people having this same issue - one person even said her throttle body was replaced, didn't fix the problem (same as happened to me), but when she brought it back, the mechanic replaced the accelerator pedal assembly sensors/accelerator pedal position sensor.
I asked the dealer mechanic about this and I believe he said those sensors are part of the throttle body - and were therefore replaced last time.
Again, thanks for your help!
I'm sorry you are experiencing this issue with your Impala vehicle. Please keep us posted of the results of your latest dealer visit.
Please feel free to contact me if you have any additional questions or concerns.
GM Customer Service