[JC7798]

As the title suggests, I am having an issue where the car wont slow down when I remove my foot from the gas pedal. Once I am up to speed it acts like cruise control is on, but there is no cruise control. Maintains speed and RPM, except it will drop significantly momentarily and then go right back up to where it was when I take my foot off the gas. Occasionally is will keep RPM at 1000 or above when parking after being driven, and if I rev the engine it shoots up to 3-4000 and stays there until I put it in N and turn it off. When turning it back on immediately after, it idles just fine. Other things I am experiencing since it began is very poor gas mileage. I have done some maintenance myself: replacing the Mass airflow sensor, cleaning throttle body, new starter and some wiring that was split that caused some other trouble codes (P0102 is the only one I can remember off the top of my head, this also got rid of the hard shifting and poor acceleration) The wires I repaired were a tan one with a black stripe, a blue one with a white stripe and a solid blue one (driver side, front, near where the dipstick is).The hard shifting I was experiencing is gone and it drives very smooth now,
The above issue only appeared after everything else was done.

I tried to be as detailed as possible, if more information is needed please let me know! thanks!

 

[Sir 500mph]

Did you disconnect/remove the throttle body to clean it? Or push it open manually? You may have to do a Case Relearn if you did
This will require a GM Tech2 or HP Tuners to do. Some have also said that the Interceptor Gauge can do it as well but I don't believe the G5s ever got those. 2006 Cobalt SS CASE Relearn
If this does not work, you may need a PCM/ECM reflash. I havent personally dealt with this issue but this is just what I found in my research

 

[JC7798]

Did you disconnect/remove the throttle body to clean it? Or push it open manually? You may have to do a Case Relearn if you did
This will require a GM Tech2 or HP Tuners to do. Some have also said that the Interceptor Gauge can do it as well but I don't believe the G5s ever got those. 2006 Cobalt SS CASE Relearn
If this does not work, you may need a PCM/ECM reflash. I haven't personally dealt with this issue but this is just what I found in my research

I did end up taking it off to get it clean, the back of the butterfly was filthy; especially around the gap. I did end up opening it slightly during the cleaning but it was ever so slightly (i read conflicting information about whether or not to open it, so i tried not to just to be safe).
Excuse the question as I'm still very amateur, but this Case Relearn or the Reflash; they sound like something ill have to go to a dealership for?

 

[Sir 500mph]

Thatd probably be your best bet for the moment.

 

[Cherry GT]

I have had the high idle issue.
NOTHING HELPED, CASE RELEARN is for Crankshaft Angle Sensor Error relearn. ECM reflash and throttle body learn procedure did not work either.
The fix for mine was continue driving like it was acting and it relearned itself in about 2 weeks time and all has been fine since.

 

[Cherry GT]

HERE IS CASE INFO.

CRANKSHAFT VARIATION RELEARN (CASE Learn)

”CASE” means: crankshaft angle sensor error.
A crankshaft variation relearn must be performed if:

A diagnostic trouble code of P1336 is present.
The computer has been replaced or re-programmed.
The crankshaft position sensor has been replaced.
The engine, harmonic balancer, clutch, or flywheel
have been: disassembled, removed, or replaced.
The crankshaft position variation learning feature
enables the computer to compensate for part
manufacturing tolerances. This allows the computer
to accurately detect an engine misfire throughout the
engine RPM range. The learning process is stored in the
computer’s memory and does not have to be repeated
unless one or more of the above conditions are present.


To perform the relearn, proceed as follows:

Connect a scan tool to make sure there are no trouble
codes stored in the computer’s memory. If there is any
power train trouble code other than P1336
(Crankshaft Position Variation not learned),
the computer will disable the relearn function until the
problem that caused the code has been eliminated. Also,
make sure that the engine coolant
and oil levels are at an acceptable level.
(check it when the engine is cold)

1. Set the parking brake and block the drive wheels.
Make sure that the hood is closed.
2. Start the engine and make sure that the engine coolant
temperature is at least 158 degrees F. (70 degrees C.)
3. Turn the engine off for at least 10 seconds.
4. Select the crankshaft position variation learn procedure
(CASE Learn)on your scan tool.
5. Make sure that the transmission is in Park,
Start the engine.
6. Apply the brakes and hold the pedal firmly.
7. Follow the scan tool instructions.

Remember: That you are going to increase the
engine speed to approximately 4000 RPM.
That’s the variation learn fuel cutoff RPM
(depending upon the engine), and that it’s important
to release the throttle when the engine RPM starts to
decrease as a result of the fuel cutoff going into effect.
Failure to do such will result in over revving of the engine,
causing possible engine damage.

8. Once the engine has returned to idle, check
the status of Diagnostic trouble code P1336.
If the scan tool indicates that the CASE has been
learned, the relearn procedure is now complete.
If CASE has not been learned, check for the
presence of other power train codes.
If any exist, correct the problem,
then repeat this procedure.

This is for Rob..........
He informed me of the problem......

 

[JC7798]

Thanks for your help guys! Nice to finally have some light shed on this little issue

 

[JC7798]

I have had the high idle issue.
NOTHING HELPED, CASE RELEARN is for Crankshaft Angle Sensor Error relearn. ECM reflash and throttle body learn procedure did not work either.
The fix for mine was continue driving like it was acting and it relearned itself in about 2 weeks time and all has been fine since.

I've been driving mine for a couple weeks now while I work on making time to actually work on it again. No improvement so far.