What d90 means (lg d90 error)
An lg d90 error is a Flow Sense duct-restriction warning on an LG dryer indicating roughly 90% of the exhaust is blocked. At this level the dryer often cools and stops the cycle to protect itself. It is still an airflow warning, not a failed part, and clears once the filter and duct are cleaned.
Symptoms to look for
The signs below help confirm you are dealing with this condition rather than a different fault on your LG Dryer. You may see one of them or several together, and they can build up gradually or appear suddenly after a power event, a long door opening, or recent service.
- The display shows “d90”
- The cycle cools down and stops early
- Loads come out damp despite a long run
- Heavy lint at the filter and around the vent
Common causes
Several different faults can produce these symptoms. Working through the most likely causes in order helps separate a quick, owner-level check from a problem that needs trained service and the correct LG parts.
- Heavily clogged lint filter — airflow is badly restricted
- Blocked exhaust duct — significant lint buildup in the run
- Vent flap jammed shut — exhaust cannot escape
- Excessively long or kinked duct — chokes the airflow
Troubleshooting steps you can try
Work through these checks in order before calling for service. Stop wherever you are unsure, or where high-voltage parts, gas, the sealed refrigeration system, or a heat-pump compressor are involved, and hand the rest to a qualified technician.
- Clean the lint filter thoroughly and wash off any residue.
- Clean the entire exhaust duct and the exterior vent of lint.
- Confirm the exterior flap opens fully when the dryer runs.
- Shorten or straighten the duct and use rigid metal where possible.
Parts a technician may replace
Depending on what the diagnosis shows, a technician may inspect, test, or replace the lint filter, exhaust duct, vent flap, and transition hose. The correct part for your LG Dryer is matched from the model and serial number, and genuine LG components are fitted rather than generic substitutes so that performance, safety, and the appliance’s long working life are all protected. Confirming the failed part before ordering avoids replacing more than the fault actually requires.
When to call a technician
If d90 returns after a full cleaning, a technician should check for a collapsed duct, an undersized vent, or a Flow Sense sensor fault. When the fix calls for trained service, book a visit through our scheduling page and an experienced, qualified technician will diagnose and repair it. For manufacturer documentation and model lookup, see the manufacturer at lg.com/us.
Prevention and care
Regular care keeps this condition from returning on your LG Dryer. Keep filters, vents, and the condenser or exhaust path clean, avoid overloading or blocking airflow, check that doors and seals close cleanly, and follow the LG maintenance guidance for your model. Because this unit relies on electronic control, protect it with a stable, correctly rated power supply and have any built-in or laundry installation done to LG specification so the control never sees an out-of-range condition. If a code appears, note exactly what was shown before you reset the appliance — that record helps the technician reach an accurate diagnosis and avoid replacing parts unnecessarily.
Related help and LG resources
Browse other LG Dryer diagnostics, read about professional LG Dryer repair, look up your unit in the LG models reference, or the related d95 severe restriction, or schedule a service visit. For LG manufacturer documentation and model lookup, visit the manufacturer at lg.com/us.
