Problem: The IRS—not eFile.com—rejected your Federal Tax Return due to a PIN-related problem.
Solution: Sign into your eFile.com account, click on "My Return" on the green section in the upper left, and read the instruction message on the right: Be sure to include your signature PIN. Click "File" and follow back through the process to add this information.
If you are not sure what to do, please contact us with your questions: https://www.efile.com/tax-service/contact/efile-contact/