2007 Yukon Denali RPm increase without pedal input

specialized51 said:

Yukop2007 did you ever fix the truck? Mine is doing the same exact thing.

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Toko06 said:

I bought a OTO Fix D lite will see if I can relearn the throttle body

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YUKOP2007 said:

Looking for assistance with Idle issues in 2007 Yukon Denali 6.2 L 163,000 Miles

I had the throttle body cleaned after getting a Service code - person that cleaned it moved the throttle plate while cleaning and now we have a high idle issue.
Throttle body was not removed from the truck during cleaning.
At idle in park, RPM goes up to 2000 approx.
Tried the manual relearn, brought the truck to a shop to have a scan tool relearn to no avail. Truck seems like its trying to learn, until the 3rd start up and then the high RPM returns. Disconnecting battery will allow RPM to normalize, and as long as you don't touch the pedal, it will remain normal.

Tried the drive cycle to force a relearn, and no luck.
RPM increases without pedal input and truck is driving itself. Creating higher transmission temperature than usual.

Replaced the throttle body with a new OEM unit - same high idle issue

Tried manual reset, tool reset, driving, No luck. On 2nd restart, high idle returns.

No engine codes have fired since cleaning the throttle body. NO codes for high idle or anything else.

As soon as you put the truck in gear, the idle speed increases on its own. If you stop while in gear, the RPM will very slowly decrease down to expected, but as soon as you let off the brake the truck will increase RPM and try to drive itself.

We did a smoke test (tried to) and we did not find any leaks. We also replaced the EVAP vent selenoid and EVAP purge valve (this was 1+ years ago), because we were getting a code for gross EVAP leak. After replacing the purge valve, we have not had that code again. The RPM was high prior to and after replacing the purge valve. It did not seem to have an impact.

Completely stumped and so is our local shop - Anyone have any other ideas/suggestions on what it could be?

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Jfulps14 said:

I had a very similar issue with my 08 Tahoe after cleaning the throttle body. Sometimes when starting it would surge over 2k. Or when I parked if I did not wait 5-10 seconds for rpm to drop under 800-1k when shifting to park it would surge over 2k again. Tried the manual reset, the drive relearn, bought a relearn tool (977-002) specifically for this issue, bought a more expensive tool that advertised idle relearn but wouldn’t give me the option when plugged in, replaced the throttle body entirely.. none of it worked. Then I took it to a shop and for $25 bucks he plugged his $5,000 tool in and was able to do an idle relearn. Helped a ton but still have the issue of first acceleration doing exactly what you described. Then wait a few seconds let it drop down to normal and drives GREAT. Until it’s time to slow down for a turn or stop sign and first acceleration after, same process starts over.

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Jfulps14 said:

I had a very similar issue with my 08 Tahoe after cleaning the throttle body. Sometimes when starting it would surge over 2k. Or when I parked if I did not wait 5-10 seconds for rpm to drop under 800-1k when shifting to park it would surge over 2k again. Tried the manual reset, the drive relearn, bought a relearn tool (977-002) specifically for this issue, bought a more expensive tool that advertised idle relearn but wouldn’t give me the option when plugged in, replaced the throttle body entirely.. none of it worked. Then I took it to a shop and for $25 bucks he plugged his $5,000 tool in and was able to do an idle relearn. Helped a ton but still have the issue of first acceleration doing exactly what you described. Then wait a few seconds let it drop down to normal and drives GREAT. Until it’s time to slow down for a turn or stop sign and first acceleration after, same process starts over.

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specialized51 said:

JFulps, are you still having issues? Mine drives itself at 1K RPM like the OP’s truck.

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Marky Dissod said:

Believe it or not, I've a similar issue with a 2002 Tahoe. For clarity, it uses a mechanical throttle cable, NOT an electronic throttle signal.

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Jfulps14 said:

Yeah very similar to mine. Basically each initial acceleration after dropping sub 1k I have the problem and have learned to push it to about 2500rpm and take my foot off the pedal and wait a few seconds and it’ll relax and drop down and drive as it should. It’s such an oddly specific issue that occurs EVERYTIME that I wish I could figure out the underlying cause.

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Doubeleive said:

that should not be happening, I would connect a scanner and monitor the live data particularly the gas pedal & throttle +air, it could even be a map/maf/temp sensor issue correlation or even electrical (poor voltage)
something like that would drive me insane

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Jfulps14 said:

Yeah it’s very annoying and mildly concerning. The part of the issue that still gives me hope that it’s not a failing transmission that is gonna need to be replaced soon is two things. Firstly, the fact that it is very specific and only does it when accelerating after dropping back into first due to stopping a stop sign or starting up the car and driving with initially after it occurs it drives fantastic (unless I for whatever reason need to really floor it.) secondly we did a pan drop and filter and fluid change on the transmission fluid last week and there was no concerning debris in the pan. I do not know much at all about cars and I’m not afraid to admit that but doing some research I have learned that A 2–4 servo kit (more commonly referred to as a Corvette servo kit) could help fix my issue. We will know in the next couple days because it gets delivered l today.

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