A rotational clicking sound may be heard after the engine is turned off on some 2017-2019 Cruze, Malibu; 2018-2019 Enclave, Envision, LaCrosse, Regal, Equinox, Traverse, Terrain; and 2019 XT4 and Blazer models equipped with the GF9 9T45, 9T50 (Fig. 15), 9T60, and 9T65 9-speed automatic transmission (RPOs M3W, M3T, M3G, M3D, M3H, M3V, M3E, M3U).
Fig. 15
After engine shutoff, the Transmission Control Module (TCM) keeps the power mode in the Accessory mode for an extended period of time and the Line Pressure Solenoid stays in Dither Mode Control when there is no fluid pressure/pump, which causes the High Side Driver and Solenoid Body Assembly to have a clicking sound or buzz. The loudness and length of time of the sound may vary depending on the vehicle.
The sound is a normal design characteristic of the transmission. No repairs should be made as there are no durability concerns due to the sound.
– Thanks to Tom Ellison
