2007 GMC Sierra

Tiny
LESDANIELL@MSN.COM
  • MEMBER
  • 2007 GMC SIERRA
  • V8
  • 2WD
  • AUTOMATIC
  • 55,600 MILES
Engine light was on, had it checked at dealer, first recommendation on dealer computer to clean throttle body, I did this myself (an easy task) engine light went off, engine running smoother and much better throttle response. Only problem now is it idles at 1800 rpm, took it to dealer and they reset the computers idle, worked for a short time then back to 1800 rpm. I sprayed carb cleaner around gaskets to check for a vaccum leak, nothing. I took the throttle body back off and used a little gasket sealant on gasket just to make sure, it does have an airraid throttle body spacer on it but put it on @ 6,000 miles, can’t see that making a difference after 50,000 miles. Engine light is off and dealer finds no codes on computer.
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Tuesday, January 26th, 2010 AT 6:06 PM

7 Replies

Tiny
SERVICE WRITER
  • EXPERT
What was the original code. Before the throttle body cleaning. Preferably the code number.
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Tuesday, January 26th, 2010 AT 6:23 PM
Tiny
LESDANIELL@MSN.COM
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Sorry, I don't know.
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Tuesday, January 26th, 2010 AT 6:24 PM
Tiny
SERVICE WRITER
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See if you can find out, the dealer should have record I would think.

Also, put your VIN into this and get the calibration ID.

http://tis2web.service.gm.com/tis2web

The calibration ID will tell you if software updates are available that may be related to the high idle. Sometimes there are glitches in the powertrain management software that need updates.
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Tuesday, January 26th, 2010 AT 6:34 PM
Tiny
LESDANIELL@MSN.COM
  • MEMBER
I'll check with him tomorrow on the code#, I do remember him entering the VIN into his computer when the code was on.
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Tuesday, January 26th, 2010 AT 6:38 PM
Tiny
SERVICE WRITER
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Did you check the VIN with the site I sent?

You can also remove the Idle air control valve and clean it. You must drive at 35 mph for about 2 minutes for Idle to relearn. Suggest driving it on the highway for about 10 minutes. MAy need to clear the memory first.

Also, Check wires to throttle body and IAC they have a tendency to come apart in the insulation.

I am expecting P0121 is what was stored.
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Tuesday, January 26th, 2010 AT 6:43 PM
Tiny
LESDANIELL@MSN.COM
  • MEMBER
I found out from another source there is a GM known issue with this problem, looks like it's an ECM issue. GM has an update software the dealer has to program the existing ECM, if that don't solve the problem the ECM will have to be replaced. ECM still under 80,000 mile warranty.

Thanks
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Wednesday, January 27th, 2010 AT 3:41 PM
Tiny
SERVICE WRITER
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That was exactly what the link
I sent you would do.

Put your VIN into this and get the calibration ID.

http://tis2web.service.gm.com/tis2web

The calibration ID will tell you if software updates are available that may be related to the high idle. Sometimes there are glitches in the powertrain management software that need updates.
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Wednesday, January 27th, 2010 AT 4:02 PM

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