Buick LaCrosse May Have Dust Intrusion
This bulletin applies to 2017-2018 Buick LaCrosse vehicles. A customer may bring in their vehicle with the SES light on. When diagnosing the concern, DTC P0446 may be found.
This code may have set due to dust intrusion into the EVAP canister through the air inlet pipe. Clean the filters in the air inlet to EVAP canister, clean the line and replace the canister.
The inlet pipe with filter housing is attached to the fuel inlet pipe with zip ties. Disconnect the air inlet pipe from the EVAP canister. Remove the cover from the air inlet housing.
Remove both filters from the air inlet and blow dust out of the filters with compressed air (be sure to wear a mask and eye protection. With the EVAP air inlet pipe disconnected from the canister, blow all dust out of the pipe.
Install a new EVAP canister, reinstall filters and reconnect the air inlet pipe to the canister.