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Pete, GMC Mechanic
Category: GMC
Satisfied Customers: 28772
Experience:  GM training and dealer tech for 14+ years. Diagnostics
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I have a 2011 GMC Sierra W/T 2 WD, v6 auto with 27,000

Customer Question

I have a 2011 GMC Sierra W/T 2 WD, v6 auto with 27,000 miles. For the past two years I have experienced when driving, the engine starts bucking and shaking all warning lights go on and stalls. If I let sit for a few minutes then it starts up runs better but engine light on. One time I tapped on the throttle body and the motor smoothed out. I had it to the GMC dealer numerous times but they could not find problem. Had a local garage look at it and he found acode for throttle position sensor. He sprayed Seafoam in throttle body rest coodes and I was good for 3 months and same thing is back again. GMC dealer is out of business now so I just made apt tomorrow with Chevy dealer. Just got stuck again the other day with the same simptoms. I tapped on throttle body and left idle for have hour or so and now engine light went off on its own. I took truck to local shop to get a scan on it and he came up with throttle body sensor even though the light is off. I don't know what to tell the dealer tomorrow. Any ideas.
Submitted: 1 year ago.
Category: GMC
Expert:  Pete replied 1 year ago.

Hi my name is ***** ***** I will be happy to assist with this today.In some cases I may need more info to assist better.I apologize for any delay.

The throttle body sensor is a common component that fails on this model here.When it fails it sends incorrect signals to the computer on what position the throttle is at.When this occurs the engine computer can cause the engine to run poorly and in some cases stall out.Since it was already cleaned and did not correct the fault here I suspect the throttle body position sensor needs replaced.In some cases on some models this requires complete replacement of the entire throttle body as some are not serviced separately.

The cost for this replacement can vary depending on the model usually anywhere from $450 total parts and labor to around $700 total.I would have them check the wiring leading to the throttle body to make sure it is all o.k. as well as shorted wiring or bent terminals in the connector will also cause this as I have seen and had to repair.

If more help is needed, use the reply tab to continue our conversation. If no further assistance is needed, kindly rate my service.You can rate at any time and we can continue to work on your question as this will not close out your question.Keep in mind in some cases it can be difficult to fully diagnose or help repair your vehicle without seeing it and I work on delivering the best possible answer from what I see to work with.

Thanks Pete