This bulletin applies to 2016-2022 Buick Encore vehicles equipped with a 1.4L LE2 engine. During cold weather conditions, DTC P0234 and/or P0299 may be set. The cause is oil/moisture condensate freezing up in the turbocharger wastegate regulator solenoid valve (TCV).
Remove the turbocharger wastegate regulator solenoid valve. Drain the TCV by turning the valve upside down. Using clean shop air regulated to 15-20 psi, blow through all three ports for five seconds each. Repeat this twice. Check port number two to ensure that the spring gets lifted off the seat. This will be determined by the compressed air not dead-heading when applied to port number two. When applying air to this port, a small amount of air should be observed at port number three and even less air will be noticed at port number one. If this does not happen, the TCV plunger may have hardened deposits from hot operating conditions which will impede TCV plunger movement, and the TCV should be replaced.
