Operation CHARM: Car repair manuals for everyone.

Bi-Level Mode

When the driver selects the BI-LEVEL mode, cool air is delivered through the instrument panel outlets while warm air is delivered through the floor outlets. The HVAC control module grounds the lower mode valve solenoid control circuit. When the solenoid is grounded, vacuum is supplied to the defrost actuator. The actuator retracts, opening the mode and heater doors.