This bulletin applies to 2018-2020 Mazda6 vehicles equipped with SKYACTIV-G 2.5T engines produced before Dec. 27, 2019.
Some customers may experience the check engine light on with DTC 222.9:00 stored in PCM memory. BARO sensor circuit high input.
This concern will most likely occur on vehicles that have aftermarket wax applied in the engine compartment. Aftermarket wax may adhere to the breather hole located at the bottom of the PCM, which may collect dust and result in a plugged filter. This breather hole is actually a filter for the air pressure sensor in the PCM. When the PCM gets hot, the internal air pressure may rise due to the plugged filter and result in the DTC.
To eliminate the concern, the shape of the PCM bracket has been modified to not cover the breather hole and eliminate a gap between it and the PCM that may promote the residual liquid wax. If the breather hole is plugged, it is impossible to clean the filter. Do not attempt to disassemble the PCM.
Remove the PCM with brackets. Visually check if the clearance between the PCM and the lower bracket is narrow and/or the breather hole looks dirt. If not, there may be another cause for the concern.
If the breather hole is plugged, install a new PCM with a modified bracket. Perform PCM configuration and immobilizer system-related part programming according to instructions on MGSS.
P/N PART NOTE
PYH7-18-885A........bracket
PYFL-18-881.......... PCM.......................US spec
PYFN-18-881.......PCM......................Mexico spec
About the Author
Mike Mavrigian
Motor Age Editor
Mike Mavrigian has written thousands of automotive technical magazine articles involving a variety of specialties, from engine building to wheel alignment, and has authored more than a dozen books that crisscross the automotive spectrum. Mike operates Birchwood Automotive, an Ohio shop that builds custom engines and performs vintage vehicle restorations. The shop also features a professional photo studio to document projects and to create images for articles and books.