New Throttle Body now what

[Mberry]

Hey y’all I have a 2009 aveo and I researched that when it throws code 0121 to just replace the throttle body. I did and now the car won’t stat running it idles rough and slowly drops rpm until it quits. Did I miss something?

[Deano]

I think we might need a little more information to help us understand:

1) Was the new throttle body a GM / AC Delco part? Or was it made by someone else?
2) Did you do any re-learning steps after installing the new throttle body?

Thanks,
Deano

[Mberry]

I think we might need a little more information to help us understand:

1) Was the new throttle body a GM / AC Delco part? Or was it made by someone else?
2) Did you do any re-learning steps after installing the new throttle body?

Thanks,
Deano

Ok, so it is a factory OEM/AC Delco from rock auto.

And I was unaware of “re-learning” steps

[Deano]

Just in case you haven't already got this information:

According to the HELM Manual page 9-934:
Idle Learn Procedure Without (Tech2) Scan Tool

Note: Do NOT perform this procedure if DTCs are set.

1) Start and idle the engine in park/neutral for 3 minutes.
2) With a scan tool, monitor the desired and the actual engine speed.
3) The ECM will start to learn the new idle cells and the desired engine speed should start to decrease.
4) Ignition off for 60 seconds.
5) Start and idle the engine in park/neutral for 3 minues
6) After the 3 minute run time the engine should be idling normal.

- During the drive cycle the malfunction indicator lamp (MIL) may illuminate and idle speed DTCs set. If idle sped DTCs set, clear the DTCs so that the ECM can continue to learn.

- If the vehicle is driven for more than 10km (6 miles) a BARO update is necessary so the ECM can continue to learn. To update the BARO, accelerate to wide open throttle (WOT) and then release the throttle. - If the engine idle speed has not been learned the vehicle will need to be driven at speeds above 70 kph (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 (maybe they mean step 5)
8. Once the engine speed has returned to normal, clear the DTCs with a scan tool.

[Deano]

I've inserted the Notes in between Step 6 and Step 7 as shown in the Manual.