Denso Air Conditioner Error Code OL

The OL code on a Denso air conditioner means the compressor overload relay has activated due to high temperature buildup inside the compressor. This is a protective shutdown designed to prevent compressor damage. The most common trigger is a refrigerant leak that causes the system to run low on charge, forcing the compressor to overheat. The system will not resume normal operation until the underlying cause is corrected and the controller is reset.

No, you should not attempt to bypass or ignore the OL error. The overload relay has shut down the compressor specifically to protect it from heat damage. Continuing to force operation without resolving the root cause, typically a refrigerant leak or airflow restriction, risks permanent compressor failure, which is a significantly more expensive repair than addressing the original problem.

Repair costs vary depending on the cause and severity of the problem. A straightforward refrigerant leak repair combined with recharging typically falls in the range of $150 to $500 or more, depending on the leak location, refrigerant type, and labor rates in your area. If the compressor overload relay itself needs replacement, parts and labor add additional cost. A full compressor replacement, needed only in severe cases, can range from $800 to several thousand dollars.

Fixing the OL code requires identifying and repairing the source of any refrigerant leak, then recharging the system with the correct amount of refrigerant. Once the repair is complete, the controller must be manually reset to clear the fault. You should also check the condenser coil for dirt buildup and confirm the condenser fan is operating correctly, as restricted airflow can contribute to compressor overheating.

A controller reset is required as part of the repair process, but it should only be performed after the underlying cause has been corrected. If the refrigerant leak is repaired and the system is properly recharged before the reset, the code should clear and normal operation should resume. Resetting without fixing the root cause will result in the OL code returning once the compressor overheats again.