TSB: Camaro Exhaust Valves

This bulletin applies to 2016-2024 Chevy Camaro vehicles equipped with an LGX, LT1 or LT4 engine. The check engine light may be on and an exhaust noise may be present. DTC P12FD or P12F0 may be set. This concern may be caused by an exhaust actuator that was installed but the learn procedure was not completed. This concern will occur on vehicles that have had recent exhaust system work.

Some vehicles are equipped with Passive Exhaust Valves (PEV) that are purely mechanical in nature. Ther are spring operated and they are not able to be externally controlled. These valves are also referred to as AFM (active fuel management) valves.

If the vehicle battery becomes discharged or disconnected for any reason, the cylinder deactivation laves and/or flow control valve relearn procedure may also need to be performed. If not, the exhaust valves may hunt/surge for position and continue to make an audible noise.