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Hi im new to the site and i have a 09 cobalt sedan with a 2.2 auto, i recently cleaned the throttle body and reinstalled it then afterwards the idle seem to be running really high about around 2000 rpm then gradually come back down. so i took off the negative cable for bout 15 min's then it seem to run fine but now im having an issue with another code "P0223" which is a tps/pedal switch sensor reading to high. does this mean i have to replace the pedal sensor or do something with disabling the battery? any help would be appreciated as this is our only ride.

thanks
 

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Did you remove the throttle body from the intake?

---------- Post added at 03:00 PM ---------- Previous post was at 02:58 PM ----------

Did you leave the key in the ignition?

---------- Post added at 03:16 PM ---------- Previous post was at 03:00 PM ----------



Throttle Actuator Control (TAC) System Description




The engine control module (ECM) is the control center for the throttle actuator control (TAC) system. The ECM determines the driver's intent based on input form the accelerator pedal position sensors, then calculates the appropriate throttle response based on the throttle position sensors. The ECM achieves throttle positioning by providing a pulse width modulated voltage to the throttle actuator motor. The throttle blade is spring loaded in both directions, and the default position is slightly open.

Modes Of Operation
Normal Mode
During the operation of the TAC system, several modes, or functions, are considered normal. The following modes may be entered during normal operations:

• Minimum pedal value--At key-up, the ECM updates the learned minimum pedal value.

• Minimum throttle position values--At key-up, the ECM updates the learned minimum throttle position value. In order to learn the minimum throttle position value, the throttle blade is moved to the Closed position.

• Ice break mode--If the throttle blade is not able to reach a predetermined minimum throttle position, the ice break mode is entered. During the ice break mode, the ECM commands the maximum pulse width several times to the throttle actuator motor in the closing direction.

• Minimum pedal value--At key-up, the ECM updates the learned minimum pedal value.

• Battery saver mode--After a predetermined time without engine RPM, the ECM commands the battery saver mode. During the battery saver mode, the TAC module removes the voltage from the motor control circuits, which removes the current draw used to maintain the idle position and allows the throttle to return to the spring loaded default position.

Reduced Engine Power Mode
When the ECM detects a condition with the TAC system, the ECM may enter a reduced engine power mode. Reduced engine power may cause one or more of the following conditions:

• Acceleration limiting--The ECM will continue to use the accelerator pedal for throttle control, however, the vehicle acceleration is limited.
• Limited throttle mode--The ECM will continue to use the accelerator pedal for throttle control, however, the maximum throttle opening is limited.

• Throttle default mode--The ECM will turn OFF the throttle actuator motor, and the throttle will return to the spring loaded default position.

• Forced idle mode--The ECM will perform the following actions:

- Limit engine speed to idle positioning the throttle position, or by controlling the fuel and spark if the throttle is turned OFF.

- Ignore the accelerator pedal input.

• Engine shutdown mode--The ECM will disable fuel and de-energize the throttle actuator.

---------- Post added at 03:18 PM ---------- Previous post was at 03:16 PM ----------

TP sensors are part of the throttle body and as far as I know cannot be replaced.

---------- Post added at 03:31 PM ---------- Previous post was at 03:18 PM ----------

Throttle Body Cleaning
Remove the air cleaner outlet duct.
Inspect the throttle body bore and the throttle valve plate for deposits. You must open the throttle valve in order to inspect all of the surfaces.
Notice: Do not subject a throttle body assembly which contains the following components to an immersion cleaner or a strong solvent:

• Throttle position (TP) sensor

• Idle air control (IAC) valve

• Sealed throttle shaft bearings

The cleaners will damage the electric components or sensors.

The cleaners will damage some of these components that contain seals or O-rings.


Solvents can wash away or break down the grease used on non-serviceable throttle shaft bearings.


Never use a wire brush or scraper to clean the throttle body. A wire brush or sharp tools may damage the throttle body components.


Do not use a cleaner that contains methyl ethyl ketone. This extremely strong solvent may damage components and is not necessary for this type of cleaning.


Clean the throttle body bore and the throttle valve plate using a clean shop towel with Top Engine Cleaner, GM P/N 12346535, (Canadian P/N 992872) or Saturn P/N 21007129 or an equivalent product.

Important: DO NOT prop open the throttle blade with the ignition key in the ON position as it may set a diagnostic trouble code (DTC).
 

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Discussion Starter #3 (Edited)
yes, i removed the throttle from the intake but i didnt disassemble anything on the throttle body itself, just cleaned with a cloth on the inside is all....Rite now it reads engine reduce power and my traction control light is on.

---------- Post added at 02:34 PM ---------- Previous post was at 02:34 PM ----------

oh yeah, i left the key in the ignition well doing so but it was in the off position
 

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You don't have to have the key on to decalibrate. Did you try flooring it until limiter kicks in and releasing as soon as it does. This is suppose to reset the limits in the "ECM". Other than that I don't know for now, if you didn't drop it you should not have damaged the tb. Check the connection and maybe disconnect battery again without key in ignition.
 

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Discussion Starter #5
Ok ill try those, i didnt floor it but ill give it a shot...

---------- Post added at 05:54 PM ---------- Previous post was at 04:58 PM ----------

I tried flooring it and revved to bout 4000 rpm but still says engine reduce power and traction control is still off.
 

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Yes you will need to clear the code now.

---------- Post added at 07:56 PM ---------- Previous post was at 07:55 PM ----------

Did you shut it down after the rev and restart?
 

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Discussion Starter #7
Oh no i didnt...

---------- Post added at 08:31 PM ---------- Previous post was at 07:10 PM ----------

So far i revved the engine and restarted it, unplug the negative battery cable, checked all the wiring and so far so good, but the idle seems to be running like it use to now. Only thing im fighting still is the "engine power reduce" and the "traction control" still off. If there's other methods to try ill really appreciate it.
 

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Discussion Starter #8
Since none above worked, would i have to replace the TAC/pedal sensor or take it to a dealer to be recaliberated?
 

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Code is not for accelerator pedal position sensors, code is for throttle position sensors.
 

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20cobalt09,

I see you guys are trying to resolve your concern. If you do decided to have your dealership assist you, please let us know. You can private message us your name, VIN, phone number, and Chevrolet dealership.

Erica Tiffany
Chevrolet Customer Care
 

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Discussion Starter #11
Well, i finally had it and took it in to the dealership and come to find out i need a new ecm and which cost 500 bucks in which i dont have at the moment but i did find a used one at a salvage yard for 65 bucks, same yr and all. My question is if i swap that ecm to mine would i need to take the car back to the dealership to reset it or would it be alright? right now i cant afford the new ecm cause this was unexpected and i thought maybe i take it back to the dealer to resert the comp it would solve the problem but only to come to find out my problem would take a big chunk out of my wallet...
 
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