DTC 422, 423, 424 & 425: Self-Adjustment Of Damper Motors (Temperature Driver, Temperature Passenger, Air Distribution & RECIRCULATION) Faulty

Ensure damper, link, cam discs and damper motor can move easily and smoothly to limit position for applicable damper motor. Ensure damper motor is correctly installed. Repair damper motor as necessary. Perform self-adjust procedure. See DAMPER MOTOR LIMIT POSITION SELF-ADJUSTMENT  under ADJUSTMENTS.