Got this code today on my morning drive. Bank 1 AFM is stuck open according to the decoder. I searched the forum and the threads are a bit old 2020/21 and it seems dealers were shotgunning solutions. Anyone have this issue recently? I do have a Borla ATAK that’s been in the car for two years with no issues.

 

Most likely a bad valve actuator. Could try and do a relearn. You can buy a Launch X431 (GM version) that will do the valve relearn. If it's a bad valve actuator it should be covered under warranty. Assuming they don't give you grief for the aftermarket exhaust. I've had this code show up on the track. Hasn't happened in the last 6 or 7 events.

 

If it’s the valve actuator it’s probably not covered by the powertrain warranty (I have a 2021), but will be covered by my GMPP. Think I’ll just bring it in and let my dealership do the relearn so they are part of the the process in case they need to replace.

 

Any answer you get on the forum, will be shotgunning solutions. The code P12F0 is part of a family of codes all pointing to the same, lengthy diagnostic procedure. Looks to me like in the Service Manual it refers to bank 2. But whatever. Depending on the results of the diagnostic procedure, it could be a circuit issue, an actuator issue, or an issue with the valve in the muffler itself.

As you probably know, it might be resolved by a simple relearn procedure for the AFM valves.

As for being covered by the warranty or a protection plan, that is less likely since you have an aftermarket muffle system.

 

A relearn may be considered "software" and is usually excluded from coverage. Best of luck

 

Mike - keep in mind that Borla has a 1 million warranty and their customer service is supposed to be excellent. Don't hesitate to get them into the loop.

 

Contact Borla to hear what they have to say

 

as a suggestion when that occurs have OnStar run diagnostics so u have a record in case the car clears the code

 

Not true. I have a 2021 with a little over 13,000 miles that I took delivery of in February of 2021. My car had a valve body replacement done at the end of September because the DCT decided to skip the even gears. The replacement was All covered under the powertrain warranty.

 

The Cylinder Deactivation Exhaust Flow Control Valve actuator is not part of the of the powertrain and will not be covered once the 3/36 B2B warranty has expired. It is an electromechanical component that mounts on the muffler. There are four if you have NPP, two of them are to control sound druing V4 mode that all C8s have, and the other two actuate the tailpipe flow control valves in the muffler in accordance with the engine sound setting if you have NPP.

The valve body that you mention is an internal transmission componenet is a powertrain component and will be covered by the powertrain warranty.

In the OP case, the presence of the aftermarket Borla Atak system might complicate a decision about whether or not the Chevrolet Protection Plan (no GMEPP any more) will covert it. Procedures almost always require the tech to check for aftermarket components that might affect the diagnosis procedure. The harness, and the actuators are of course not part of the aftermarket muffler, but rather are reused. That is, when the aftermarket muffler is installed, the existing actuators in the car are removed from the old muffler and installed on the new muffler. So, "technically", if an actuator valve is the problem then its likely a defect in what should be a covered compoenent (under the Platinum Protection Plan or the B2B). But since it connects directly to the aftermarket muffler, there is a risk.

 

Thanks for the clarification. I hear the word valve and I automatically think of transmission. I forgot about the exhaust.

 

Had a valve body replaced on my ‘20 at 3400 miles. Cost would have been about $3,400 but covered under warranty

 

I’ll give my SA a call on Monday and schedule a visit. They installed the Borla system and seem pretty “fair” in their business practices. I agree there is no guarantee that they will play nice, but I’ll give them a shot. If there is an issue, then Borla is up next (their main office is just 40 minutes away).

Thanks for all the thoughts and ideas, I’ll keep everyone informed.

 

The Chevrolet Platinum Protection Plan is an exclusionary plan and I didn't see anywhere in the contract that it says it excludes software. Did you see it listed somewhere in the contract as excluded? That would be worrisome since many problems are blamed on software and the dealer will perform a reflash as a first step.

 

I downloaded the contract and searched software and it did not turn up. If a relearn was needed it would be because of a change in the actuator or travel in the valve, and would be hardware I would think. The software did not change or fail. But...since its an aftermarket muffler system, there is still a risk.

 

So….made an appt to bring it in…10 days from now before they can look at it. Been told it will take 3 days to “fix”. In the meantime I’ve ordered a Launch Elite reader to see if I can drill down on the issue and perhaps the relearn process will fix the issue. It seems I have the time to try at least. Anyone with this reader? Anything I should be aware of?

 

Got the reader….Amazon delivered same day!

Fiddled a bit around until I found the relearn menu. The exhaust valves calibrated OK, one of the AFMs did not “meet the requirement”. So unless it’s electrical, looks like the actuator is at fault. Car doesn’t sound any different, drives just fine, performance is the same.

 

Actuator or a stuck valve - will be interesting to see what the dealer says. Did they say why it will take 3 days to "fix" it? That would make me nervous since they didn't even diagnose the problem yet. Is the Master Corvette Tech (Donny) going to work on it?

 

Thats right. Until the diagnostic procedure is followed, it could be electrical, the actuator, or the valve on the muffler. HIghest likihood is the valve on the muffler itself (in my opinion), which would make something for Borla to deal with.

 

Yes, it’s a Donny availability issue.