Four flashes indicate safety sensors are misaligned.
As with any remote controller, problems with Craftsman garage door remotes are usually due to an exhausted battery. The door opener motors have programmed self-diagnostic functionality though which will help you isolate whether the problem is with the door or the remote. The "Learn" button on the motor has a diagnostic LED (light emitting diode) adjacent to it that flashes in a sequence, then pauses, and then flashes the sequence again. If you know the sequence, you can diagnose the problem and fix the garage door remote control that's not working Does this Spark an idea?
Instructions
1. Replace the battery in the remote control if the remote control doesn't work.
2. Check for obstructions at the door if the remote control is erratic. For example, the door will not close or reverses suddenly and the lights blink on the motor unit.
3. Reprogram the remote control. Press the learn button on the motor and release it. Within 30 seconds, press and hold the button on the remote that you are having a problem with. Release the button when the motor unit light blinks.
4. Test the remote control.
Tags: remote control, door remote, button motor, door remote control, flashes sequence, garage door