What causes water accumulation in the Envision's cabin?

[DelSawyer]

U-channel drain ports at both ends are blocked, or the drain pipe (for A/C condensate) at the lower outlet of the A/C evaporator drip pan is detached or clogged. Below are relevant details: Blocked drain ports: When the U-channel drain ports at both ends are blocked, water sprayed onto the windshield during car washing flows down into the U-channel. The air intake for the external circulation mode is located on the right side of the channel, and accumulated water in the channel submerges the intake, allowing water to enter the air ducts. Solutions: Open the U-channel cover plate, remove debris or sludge inside the channel, and clear the drain ports at both ends. From the exposed end of the condensate drain pipe under the car exterior, use an air pump to blow air inward to unclog the pipe. Check the connection between the interior condensate drain pipe and the A/C evaporator drip pan for detachment or signs of aging/cracking, and address as needed. The drain pipe (for A/C condensate) at the lower outlet of the A/C evaporator drip pan may be detached or clogged.