Electronic Lock Codes-Housing Services - Carnegie Mellon University

Electronic Lock Codes

Each electronic lock has two indicator lights that identify the status of the lock when a key card is inserted. Pay close attention to the lights on the lock of your room door. These lights can tell you the state of your lock when you dip your card, which may prevent you from being locked out. If you require assistance with your card or electronic lock, please make note of the light patterns displayed on the lock(s). This information greatly assists with troubleshooting your problem.

Using Your Card Key to Enter Your Room

Common Key Card Errors

Light Pattern


Solid GREEN Your card is valid and you can open the door.
Solid GREEN and Solid RED Your card is valid, but you need to enter a PIN before the door will unlock.
Flashing GREEN The door was previously double dipped and is already unlocked.
Solid GREEN and Blinking RED Your card is valid and the door can be opened, but the lock batteries are low. Submit a maintenance request to have the issue corrected. If the batteries die, you will be locked out.
Alternating GREEN and RED Your card has expired, is not valid yet or is being used outside a permissible time frame for the lock.
Solid RED
(immediately after dip)
Your card is not valid for this door or has been canceled by a new card. Please visit the Housing Services office for assistance.
Solid RED
(delayed after dip)
The lock cannot read your card. You may have dipped your card too fast; try again. If you are still having trouble, visit the Housing Services office. If you need to replace your ID card, you should visit the Card Office in Warner Hall to receive a new one for a small fee.
Flashing RED This door is blocked for all users.