# Traction Control Light, Stabilitrak Light, Check Engine Light, Engine Power Reduced



## brianhannon (Nov 19, 2015)

Hey Guys,

So my 2011 Eco sat for a few days while I took a motorcycle trip up into northern Michigan this past weekend (which is beautiful by the way!). I came back and fired it up and noticed when taking off that the steering felt a bit loose for some reason. My speedometer also read zero. About a mile down the road, the service traction control and service stabilitrak notifications came up. At this point, my steering instantly tightened up and my speedo started working. I also noticed that the engine was limited to 4000 RPM and my cooling fan came on full blast. The car went into a reduced power mode. A few more miles down the road, the check engine light came on with codes P0502 (Vehicle speed sensor A low input) and P0507 (Idle Air Control System RPM Higher than Expected). I reset the codes and they came right back on. I also unhooked the battery and have had no luck. 

I know these 1.4's have cam cover vacuum leak issues, so I'm leaning towards that being the problem. I put my finger over the diaphragm on the cover, but there seems to be no issue there. The P0507 makes sense in this aspect and I've heard that traction control lights come on when this is an issue as well. I have already had the cam cover replaced once before the car hit 100k. It's only been about 20k since this change, but could still be an issue since there was a design flaw here on GM's part. 

Another cause I've heard is a poor crimp on the negative battery cable causing a low voltage issue.


What do you guys think??


Thanks!

Brian H.


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## brianhannon (Nov 19, 2015)

I've also checked the check valve in the intake manifold according to the detailed PCV valve cover issue thread, and everything checks out OK.


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## Robby (Mar 1, 2013)

Start with the cable....10 yr warranty.

No point in looking for electrical concerns till that is out of the equation.

Rob


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## Blasirl (Mar 31, 2015)

Warranty


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## brianhannon (Nov 19, 2015)

Update*** 

I've had the negative cable replaced, still the same issue. I've also replaced the speed sensor in the transmission (addressing P0502). I reset the codes and still have the same issue. P0502 is now the only code being shown in addition to the service stabilitrak and service traction control. I have also noticed that when I reset the codes and drive the first few hundred feet (before the lights come back on), the fuel gauge is randomly moving around from 1/2 to full (I have a full tank). After the service lights turn on, the fuel gauge and speedometer begin to work properly. Could this be stemming into an issue with the cluster??

Thanks!


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