Check Engine Light - Code P12F0
Thread Starter
Intermediate
Joined: Nov 2020
Posts: 30
Likes: 8
Check Engine Light - Code P12F0
Anyone experienced a check engine light in the C8? After 1100 miles my check engine light is on. OnStar ran a diagnostic to reveal code P12F0 - The Emissions System is not performing as expected. An issue has been detected in the Exhaust Emissions System which monitors and controls exhaust gases released into the air from the engine. If the vehicle is continually driven with this light on, the emission controls might not work as well, the vehicle fuel economy might not be as good, the engine might not run as smoothly and could lead to future repairs. Service within 7 days. OnStar cleared the code so my light is off now. The dealership says to bring the car in for service.
Anyone have experience with code P12F0?
Anyone have experience with code P12F0?
Race Director
Joined: Nov 2005
Posts: 14,548
Likes: 1,539
From: Supporting the Corvette Community at Abel Chevrolet in Rio Vista, CA 707-374-6317 Ext.123
St. Jude Donor '08
Anyone experienced a check engine light in the C8? After 1100 miles my check engine light is on. OnStar ran a diagnostic to reveal code P12F0 - The Emissions System is not performing as expected. An issue has been detected in the Exhaust Emissions System which monitors and controls exhaust gases released into the air from the engine. If the vehicle is continually driven with this light on, the emission controls might not work as well, the vehicle fuel economy might not be as good, the engine might not run as smoothly and could lead to future repairs. Service within 7 days. OnStar cleared the code so my light is off now. The dealership says to bring the car in for service.
Anyone have experience with code P12F0?
Anyone have experience with code P12F0?
Thread Starter
Intermediate
Joined: Nov 2020
Posts: 30
Likes: 8
I understand. Thanks. Since OnStar cleared the code and the check engine light is currently off, is it safe to assume if the valve remains stuck open would check engine light come back on? Looks like I'll need to take a trip to the dealership.
2nd Gear
Joined: Dec 2020
Posts: 2
Likes: 0
From: Michigan
Diagnostic Code
Anyone experienced a check engine light in the C8? After 1100 miles my check engine light is on. OnStar ran a diagnostic to reveal code P12F0 - The Emissions System is not performing as expected. An issue has been detected in the Exhaust Emissions System which monitors and controls exhaust gases released into the air from the engine. If the vehicle is continually driven with this light on, the emission controls might not work as well, the vehicle fuel economy might not be as good, the engine might not run as smoothly and could lead to future repairs. Service within 7 days. OnStar cleared the code so my light is off now. The dealership says to bring the car in for service.
Anyone have experience with code P12F0?
Anyone have experience with code P12F0?
The Emissions System is not performing as expected. An issue has been detected in the Exhaust Emissions System which monitors and controls exhaust gases released into the air from the engine. If the vehicle is continually driven with this light on, the emission controls might not work as well, the vehicle fuel economy might not be as good, the engine might not run as smoothly and could lead to future repairs.
Recommended Action
Service within 7 days
Took mine in for service, now in waiting on a part.
Thread Starter
Intermediate
Joined: Nov 2020
Posts: 30
Likes: 8
I received a similar code after reaching 500 miles. P12EF.
The Emissions System is not performing as expected. An issue has been detected in the Exhaust Emissions System which monitors and controls exhaust gases released into the air from the engine. If the vehicle is continually driven with this light on, the emission controls might not work as well, the vehicle fuel economy might not be as good, the engine might not run as smoothly and could lead to future repairs.
Recommended Action
Service within 7 days
Took mine in for service, now in waiting on a part.
The Emissions System is not performing as expected. An issue has been detected in the Exhaust Emissions System which monitors and controls exhaust gases released into the air from the engine. If the vehicle is continually driven with this light on, the emission controls might not work as well, the vehicle fuel economy might not be as good, the engine might not run as smoothly and could lead to future repairs.
Recommended Action
Service within 7 days
Took mine in for service, now in waiting on a part.
Instructor
Joined: Nov 2011
Posts: 119
Likes: 34
So many problems with this car, both software and hardware, not to mention cheap failing parts. GM is trying to cut every corner they can, do not even fill up the Z51's with proper amount of transmission fluid-leave them all 2 quarts short to save a few bucks per unit- Shameful. I am so sick of reading about all the problems and lack of quality control I am seriously considering cancelling my 2021 Z51-us long time Corvette buyers deserved a more reliable car than this thing. Never had problems with my C5,C6 or C7 Z06's. Was really looking forward to this car but this rollout has been a disaster in every way imaginable. Sorry for all you guys having all theses problems.
Race Director
Joined: Mar 2001
Posts: 19,918
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From: Bonneville Salt Flats
See if it comes back on, being cleared. Believe me, if there is still a problem it will let you know.. One-shot (read, glitch) CELs are not that uncommon for any number of reasons... hey, it is a glorified computer. However, from the replies, it looks like GM may have another relatively wonky parts supplier. Best of luck, in any event. 
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Thread Starter
Intermediate
Joined: Nov 2020
Posts: 30
Likes: 8
See if it comes back on, being cleared. Believe me, if there is still a problem it will let you know.. One-shot (read, glitch) CELs are not that uncommon for any number of reasons... hey, it is a glorified computer. However, from the replies, it looks like GM may have another relatively wonky parts supplier. Best of luck, in any event.
Intermediate
Joined: Jan 2020
Posts: 39
Likes: 13
From: Minneapolis, MN
Anyone experienced a check engine light in the C8? After 1100 miles my check engine light is on. OnStar ran a diagnostic to reveal code P12F0 - The Emissions System is not performing as expected. An issue has been detected in the Exhaust Emissions System which monitors and controls exhaust gases released into the air from the engine. If the vehicle is continually driven with this light on, the emission controls might not work as well, the vehicle fuel economy might not be as good, the engine might not run as smoothly and could lead to future repairs. Service within 7 days. OnStar cleared the code so my light is off now. The dealership says to bring the car in for service.
Anyone have experience with code P12F0?
Anyone have experience with code P12F0?
Thread Starter
Intermediate
Joined: Nov 2020
Posts: 30
Likes: 8
I just took delivery of my C8. After about 5 miles were put on the car the check engine light came on. Took it to my dealer and they cleared it. Not sure of a specific code number but I was told that the light came on due to some detected engine “misfires”. I am not any kind of mechanic so I really don’t know what this means. The dealer couldn’t even offer up any suspected causes. I have noticed no performance issues with the car and the light has remained off since it was cleared. Hoping it was just some sort of glitch.
Thread Starter
Intermediate
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Instructor
Joined: Mar 2007
Posts: 175
Likes: 9
From: Clermont, FL
The code I’m getting is p0700. Now I have to look that up.
just talked to dealer, I’ll be bringing in it in Monday. I’m hoping it’s nothing serious, I would hate not having my car for Christmas. Better safe then sorry. I will give an update Monday.
just talked to dealer, I’ll be bringing in it in Monday. I’m hoping it’s nothing serious, I would hate not having my car for Christmas. Better safe then sorry. I will give an update Monday.
Last edited by Keiffer; Dec 19, 2020 at 08:27 AM.
Thread Starter
Intermediate
Joined: Nov 2020
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As soon as the problem is fixed ... it returns. 
Ten miles into my morning drive and the CEL is on. My OnStar membership has expired, so only a simple text message stating, “Diagnostic Alert: Service your emissions system in your 2020 Corvette within 7 days.” Now I’m back at the dealership. Code P12F0 on the laptop. Service representative says the actuator is stuck open. Now Service is calling GM.
Ten miles into my morning drive and the CEL is on. My OnStar membership has expired, so only a simple text message stating, “Diagnostic Alert: Service your emissions system in your 2020 Corvette within 7 days.” Now I’m back at the dealership. Code P12F0 on the laptop. Service representative says the actuator is stuck open. Now Service is calling GM.
Last edited by Jazzar35; Dec 22, 2020 at 01:45 PM.
Thread Starter
Intermediate
Joined: Nov 2020
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Dealership service department pulled the exhaust again. In consult with GM they are replacing the entire cat back performance exhaust system. GM is aware of an over heating issue with the exhaust that causes problems with the actuator valves. Parts ordered, unknown when they will arrive. I was advised to avoid track mode.
