Any GM Techs? Tahoe High-Idle Question
 

Cleaned the throttle body in my wife's Tahoe this weekend. 2007 5.3. Was throwing a 0121 TPS code - after cleaning the code has gone away.

Removed Throttle Body, pulled the butterfly off, and thoroughly cleaned.

Not it appears to be having a tough time re-learning the Idle.

When you start it with Remote Start, all is fine, but if you start it on the key sometimes it runs up and idles above 2500.

I've done the Idle Re-Learn procedure of idling for 3 minutes, turning off, repeating, etc.....

Any ideas?

Throttle Learn

Important: Do NOT perform this procedure if DTCs are set. Refer to Diagnostic Trouble Code (DTC) List - Vehicle .

1. Start and idle the engine in PARK for 3 minutes.

2. With a scan tool, monitor desired and actual RPM.

3. The ECM will start to learn the new idle cells and Desired RPM should start to decrease.

4. Ignition OFF for 60 seconds.

5. Start and idle the engine in PARK for 3 minutes.

6. After the 3 minute run time the engine should be idling normal.

Important: During the drive cycle the check engine light may come on with idle speed DTCs. If idle speed codes are set, clear codes so the ECM can continue to learn.

⇒ If the engine idle speed has not been learned the vehicle will need to be driven at speeds above 70 km/h (44 mph) with several decelerations and extended idles.

7. After the drive cycle, the engine should be idling normally.

⇒ If the engine idle speed has not been learned, turn OFF the ignition for 60 seconds and repeat step 6.

8. Once the engine speed has returned to normal, clear DTCs.

This information is straight from GM's website. Be sure to leave key off for 60 secs between key cycles. If it still wont relearn dissconnect battery for 60 secs and retry.

i was going to say dis connect the battery

Tried the above on Saturday night.

I found a number of posts on tahoeforum.com that says some of them took 100+ miles to get sorted out. Personally, I think that is ridiculous and I'm certainly not lucky enough for this thing to work itself out, but my wife drove it to work today - about 30 miles each way so I'll keep my fingers crossed.

trade it in, thats what i did to my tahoe. :lolhit:

but it had 240k miles & never had any engine issues. drivetrain began acting up & i wanted better mpg

take it to the dealer or find a friend with a tech2 and candi module. there is a updated side cover for the throttle body which replaces the sensor instead of the whole throttle body. clean the carbon off the plate and perform idle relearn with a tech2 .

fixx
 

+1,,too bad he is so far away,,i got a vtronics tec II flash..

Replace the iac,that controls the idle,,the crud gets inside of them and gm made toem so if you use like throttle body cleaned it mess's up the plastic inside the little motor and sticks..

no IAC on a 07 5.3 tahoe. its fly by wire and the blade controls idle.

Are they going to have to replace the sensor to get it to idle right? Just because I cleaned the throttle body?

Today it ran fine for my wife all day, and then she got home and it shot up to 2500 when she put it in park.

fixx
 

scratch!! didnt see the 2007 part lol,,i forgot that one has a gear box lol...

SES Light, Idle Surge, and/or Reduced Engine Power Mode with DTCs P0068, P0121, P0506, P0507, P1516, P2101, P2119, and/or P2176 - Clean Throttle Body and Perform Idle Learn reset








This PI was superseded to update model years and add information concerning idle surge, reduced engine power mode, and/or DTCs P0068, P0121, P1516, P2101, P2119, and/or P2176 that may be experienced on high mileage vehicles. Please discard PIP4578.
--------------------------------------------------------------------------------

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Condition/Concern:


As carbon builds up in the throttle body of a high mileage vehicle, the ECM/PCM learns to compensate by increasing the throttle plate angle.

If enough carbon builds up, an idle surge, deceleration surge, tip-in hesitation, reduced engine power mode, and/or DTCs P0068, P0121, P1516, P2101, P2119, and/or P2176 may be experienced on high mileage vehicles.

If the throttle body is cleaned without performing an "idle learn reset/reset idle learn" with the Tech 2, the ECM/PCM may continue to compensate for previous carbon build up, causing it to return with a similar concern as well as DTCs P0121, P0506, and/or P0507.

In a similar fashion, if the ECM/PCM of a high mileage vehicle is replaced and/or reprogrammed without performing the Throttle/Idle Learn outlined in SI, the ECM/PCM may no longer compensate for existing carbon build up in the throttle body, causing it to return with a similar concern as well as DTCs P0121, P0506, and/or P0507.

Recommendation/Instructions:


If SI diagnosis does not isolate the cause of this concern, inspect the throttle body bore and plate for obvious carbon build up.

If carbon is present, follow the Throttle Body Cleaning Procedure in SI to clean the throttle body.

After ensuring that the throttle body bore and plate are clean, perform an "idle learn reset/reset idle learn" with the Tech 2 and re-evaluate the concern.

Notice: Depending on the vehicle you are working on, the "idle learn reset/reset idle learn" is normally found on the Tech 2 ECM menu for Module Set Up or Special Functions/TAC System.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.




GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.





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thats a TSB right my gm service info website

Thanks. I guess I'll take it in. **** like this pisses me off, there is no ****ing reason this needs to be done by the Dealer.

try disconnecting the battery and touching the cables together. then just drive it normally. sometimes that works

I talked to the dealership today and the guy said it was only 109.50 to reprogram the ECM. Said that by pulling the butterfly out that I had possibly REALLY unset the positioning. I don't have time to deal with it now since I'm heading to texas in the morning so I'm just going to drop it off.

If you have a p0121 it more than likely needs a throttle position sensor (the black cover on the side of the throttle body) and cleaning. And an idle learn reset. As far as the 109.50, thats some bull$hit because an idle learn reset is done with the tech 2. Its not an ecm reflash. I personally have never taken the throttle blade off but it could be possible that you have something off a little. Im not sure on that part though. Hope u get it figured out.

tell the dealership you want a print out of the programming after the program is complete. and you want the screen printed that shows the before and after calibrations of the pcm. this way they arent blowing smoke up your a$$. we get an hour for a pcm reflash and idle learn. im guessing the labor rate is 109.50/hr at the dealerhship.

come on guys were all GM techs here,,a hour is not out of line,,the bulletin calls for a reflash on most year trucks,,and even if his truck has the latest calbration in the ecm the only way you would know that is by going thrue the steps,,by the time you bring the car in your stall hook up your MDI and get GDS2 running on your lap top,,run it thrue TIS to verify calibration and then hook up yout Tech2 to relearn min idle you got the hour into it,,+ you have to live with this truck for 3 month of looking it it for free if any other driveability issues arise (come back policy)..


I find it funny how most people have no problem with paying a repair man travel time and a flat hour to come over the house and look at their dishwasher but feel the dealership is screwing them by charging a hour to fix what other shops cant because they have no access to gmglobalconnect....

by the way I have around 5k invested in my Tech2,MDI,Lap top,,so a hour is more then fair I feel

+100

The customer write up sheet even states that one hour of service charges must be agreed by the customer signature.............. even if is it "NPF".

fixx
 

+2 and and and and + the updates 1 k a year just for the one tec II..then the other 4 scanner updates..some people dont get it..

sounds more like a vacuum leak.

you might have to replace the TB

No way you messed up the throttle position, but you do need the update, and idle learn.

x3 boatnt.

They did a full ECM reflash because of the way I had pulled the entire butterfly out. I don't mind the 109.50.

I can't see how cleaning the throttle body could necessitate any new parts. It ran fine before just had the typical 0121 caused by throttle body carbon buildup