Owners of 2007-2015 Mazda CX-9 vehicles equipped with a 3.7L engine may complain about a check engine light on.
If DTCs P2A04:00 (HO2S LH circuit range/performance), P2272:00 (HO2S LH signal stuck lean) and/or other DTCs are found during diagnosis, after verifying the concern, inspect the C-34 connector for engine oil contamination.
If contamination is found, inspect the engine oil pressure switch for external leaks. If leaks are found, replace the oil pressure switch.
Clean the C-34 connector and harness of oil. Inspect the related O2 sensors. If sensors are operating correctly, clear DTCs and test drive. If O2 sensors are not operating correctly, replace as needed.
Information for Technical Service Bulletins comes from ProDemand, Mitchell 1's auto repair information software for domestic and import vehicles. Headquartered in San Diego, Mitchell 1 has provided quality repair information solutions to the automotive industry since 1918.
Mike Mavrigian has written thousands of automotive technical magazine articles involving a variety ofspecialties, 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.
