This bulletin applies to 2020-2021 Buick Encore GX vehicles. Customers may comment that the passenger side heating performance is lower than the driver side.
GDS2 engine cooling and HVAC data show that the temperature difference between the heater inlet (ECT sensor 3) and the heater outlet (ECT sensor 4) is over 86 degrees Fahrenheit when the engine is fully warmed up.
The cause is internal blockage of the exhaust manifold outlet pipe. Technicians are required to see the temperature of ECT sensor 3 and ECT sensor 4. If the difference is over 86 degrees Fahrenheit, check to see if the pipe is internally blocked using a general endoscope. Replace the exhaust manifold outlet pipe if it is blocked. The replacement exhaust outlet pipe is P/N 12703636. The pipe gasket is P/N 12666899.
