Dryer stops and displays d90; cycle ends early and clothes are damp; airflow at outside vent is weak.

Safety first: Disconnect power. Gas dryers: shut off gas supply.

Steps:

• Disconnect from house vent: Remove the exhaust hose from the back of the dryer. Shake out lint and inspect for heavy buildup. Clean or replace if needed.
• Test airflow directly from dryer: With the hose still disconnected, plug the dryer in and run a no-heat or air-dry cycle for 1–2 minutes. Stand behind the dryer and feel the airflow from the exhaust outlet. It should be strong and steady. Unplug again after test.
• If airflow from dryer is strong: The restriction is in the house duct. Use a vent cleaning brush kit or hire a professional vent cleaning service to clear the duct all the way to the outside hood.
• If airflow from dryer is weak: Internal blockage or blower issue is likely. Remove the rear panel and access the blower housing. Vacuum lint from the blower wheel and ducts. Check that the blower wheel is firmly attached to the motor shaft and not cracked or spinning freely.
• Reassemble and retest: Reconnect a clean, short, rigid or semi-rigid duct. Run a test cycle and verify that d90 does not reappear.

Note: If airflow remains weak with a clean duct and intact blower, the motor or airflow sensor system may require professional diagnosis.