Error Code P1516 and P2176
 

I think these codes relate to the throttle body, but my DIC also show ESC error and Service ESC. Is there a possibility that a sensor of some sort is throwing these codes? At idle the engine is running rough. Thanks.
Also noticed that my oil life went back to 100% when it showed 90% before all this started.

You're right, both codes do relate to the throttle body, specifically....

P1516 Chevrolet - Throttle Actuator Control Module Throttle Actuator Position Performance

Possible causes
- Faulty Throttle Actuator Control (TAC) module
- Throttle Actuator Control (TAC) module harness is open or shorted
- Throttle Actuator Control (TAC) module circuit poor electrical connection
- Check Throttle Actuator Control (TAC) module connector for water
- Binding or bent throttle plate-failed throttle body

And.....

P2176 CHEVROLET Minimum Throttle Position Not Learned

Possible causes
- Faulty Throttle Actuator Control (TAC) module
- Throttle Actuator Control (TAC) module harness is open or shorted
- Throttle Actuator Control (TAC) module circuit poor electrical connection
- Throttle plate sticking due to carbon build-up
- Engine Control Module

So you might start with cleaning the throttle body using "Throttle Body Cleaner", never use brake clean or anything like it because it'll damage the O2 sensors.

Use a lint free cloth to wipe up any excess carbon "goop", and be super careful around the throttle butterfly.

While you're at it, grap some MAF cleaner and do that too, but don't do anything but spray the shiny parts of the MAF sensor, touching it with your fingers or a rag will kill it.

Disconnecting the negative battery cable for a minumum of five minutes will clear the codes, then you can see if cleaning the throttle body fixed the problem. If not, it will set a code again, meaning more diagnostics ars required.

I'm thinking a loose wire somewhere causing the BCM or PCM to reset itself. No clue where to start, if somebody has been doing work under your hood look in the areas that they could have knocked up on something.

Also good ideas Don, I jumped on the throttle body based on my experiences with a CEL and a P2176 code, cleaning the throttle body fixed it for me with no recurrence in 30,000 miles.

Thanks for the information. Found out those codes can be caused by a mass air flow sensor connection faulty. The plug in felt and acted like it was in place but was loose. That was a new one for me. I appreciate the info you gave me anyway.

:twothumbs: Glad you got it fixed up.

You are not the first to "forget" to hook the MAF back up after a filter change.

I am having a problem and their are four codes with the P2176 being duplicated, along with P0121 and P0221. Any suggestions! I changed the spark plugs and coil pack boots and associated components. The P2176 code would not clear after several attempts at erasing them. Any suggestions? Also, I noticed that all four of the old spark plugs possessed a reddish-brown hue to the insulator surrounding the electrode. hhrsskzoo5spd.

The stain on the plugs could indicate that you are burning coolant.

Why did you change the coils? Those codes have nothing to do with the ignition.

Do you mean the "pending" code won't clear or the "historic" code. The historic codes can take several cold starts to clear.

Have you addressed the codes? Throttle body and throttle position sensor, maybe MAF sensor?

Thanks for the possible heads-up regarding the stain. My bad on coil replacement, I replaced the coil boots during the plug replacement, I have 214K miles trying to cover all bases. No, I have not addresses the other codes. Thanks, I will look into the sensor codes tomorrow. Thanks.