Owners of 2016-2024 Chevy Camaro vehicles equipped with an LGX, LT1 or LT4 engine may comment about a check engine light on and/or an exhaust noise.
Technicians may find DTC P12FD or P12F0 set. This concern may be caused by an exhaust actuator that was installed, but the learn procedure was not completed on low-mileage vehicles or on vehicles that recently had exhaust system work performed.
Some vehicles are equipped with an electronically controlled exhaust valve actuator or passive exhaust valves (PEVs) that are purely mechanical in nature. They are spring-operated and they are not able to be externally controlled.
You may need to relearn the cylinder deactivation valves using GDS2 to resolve this concern. These valves are also referred to as the active fuel management valves (AFM). They are located before or in front of the muffler.
Note: if the vehicle’s battery becomes discharged for any reason, the cylinder deactivation valves and/or flow control valve relearn procedure may also need to be performed. If not, the exhaust valves may hunt or search for position and continue to make an audible noise.
