2007 Yukon Denali RPm increase without pedal input

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?

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

I cannot personally assist you with your issue, but other members of this Forum much more knowledgeable than me in this area will chime in. The truck does have drive by wire for the accelerator pedal, so there may be an electrical-related issue, since you have already checked out the mechanical portions of the process.

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?

Click to expand...

it's one of those rare occasions where it needs a throttle body/idle relearn WITH A SCANNER.
you need a tech2 or comparable level bi-directional scanner
I would take it back to whoever did the work and report the issue has persisted since the work was done and they should take care of you no charge it only takes a few minutes.

Doubeleive said:

it's one of those rare occasions where it needs a throttle body/idle relearn WITH A SCANNER.
you need a tech2 or comparable level bi-directional scanner
I would take it back to whoever did the work and report the issue has persisted since the work was done and they should take care of you no charge it only takes a few minutes.

Click to expand...

Already tried that. We took it to a shop and also purchased a bidirectional scan tool with the functionality. We have literally tried every way of relearning.

When the throttle body was cleaned was the TPS removed from the side of it? If that is not clocked correctly during assembly it can cause idling issue. Been there.

this guy goes into a little more detail, but I believe there is a way to learn the new throttle body "module" to the vehicle I just have not done it

Will your scanner show the (throttle body) throttle position "desired" and "actual/indicated" angle percentages? If so, what are they?

89Suburban said:

When the throttle body was cleaned was the TPS removed from the side of it? If that is not clocked correctly during assembly it can cause idling issue. Been there.

Click to expand...

We replaced the entire unit, tps included

Fless said:

Will your scanner show the (throttle body) throttle position "desired" and "actual/indicated" angle percentages? If so, what are they?

Click to expand...

It doesn't give desired throttle position, just indicated. When idling normal it's at 5 or 6%. When idling high at idle it's 23%. When driving it varies.

YUKOP2007 said:

It doesn't give desired throttle position, just indicated. When idling normal it's at 5 or 6%. When idling high at idle it's 23%. When driving it varies.

Click to expand...

what scanner are you using

Doubeleive said:

this guy goes into a little more detail, but I believe there is a way to learn the new throttle body "module" to the vehicle I just have not done it

Click to expand...

Thanks! I had not found that yet. Symptoms are correct, but when I click the relearn, my throttle position jumps back to 23%. I started it and was sitting at 7% desired and actual. Shut it off and it jumps right back up to 23%.

Doubeleive said:

what scanner are you using

Click to expand...

I wasn't in the right menu. New tool, lol. When I went to that section it said desired was 20% actual was 23%. I can manually adjust it up and down, and it matches up. But it goes back up to 23% if I shut it off. I didn't monitor it while driving, so unsure outside of idle.

another member was having a pretty much identical issue before and he said the fix was it had to be learned to the vehicle, where that menu may be I do not know must be a special function though

if there is any option to do that anyway, it might take a calibration file or something, I can poke around on my tech2 later but have some errands to do first.

Maybe a faulty gas pedal position sensor?

Correlation between pedal and throttle body. is there codes when cranked after a while after it idles high? Didn't see that above. But there are I think 2 TPSs. I think set as A and B sensors. Unless u keep getting bad throttle bodies. And when the relearn is done is it saying relearn complete?

LsHart said:

Correlation between pedal and throttle body. is there codes when cranked after a while after it idles high? Didn't see that above. But there are I think 2 TPSs. I think set as A and B sensors. Unless u keep getting bad throttle bodies. And when the relearn is done is it saying relearn complete?

Click to expand...

No codes at all. A and B sensors seem to be as expected. After relearn is done it says complete. It's like it just won't save or complete the relearn.

Doubeleive said:

another member was having a pretty much identical issue before and he said the fix was it had to be learned to the vehicle, where that menu may be I do not know must be a special function though

Click to expand...

If there is, I haven't found it yet.

SpareParts said:

Maybe a faulty gas pedal position sensor?

Click to expand...

We replaced that too in this process.

I did not get time to look tonight I will try again tomorrow