Atwood 8940-III-DCLP Furnace issue

Our Atwood 8940-III-DCLP Furnace is giving me an error code. The little red light on the control board is flashing one time every three seconds. According to the sticker on the furnace it is referring to "Airflow/Limit Fault" code. I just changed the blower motor because it siezed up and was giving me the same code just before it quit. Up until then the furnace worked fine. But now I'm still getting the error. Help me please!