The electronics, including the speedometer, come and go. Sometimes they are off for a day or on for a day. Usually they stay off for a week then maybe on for a day, then back off. This happens while driving, just suddenly go off or come on. Also auto door locks do not kick in when it is off, but they will lock when electronics come back on. Started with a flickering of the odometer maybe a year ago. Keeps getting worse, hardly comes on at all anymore
Symptom indicates the possibility if a poor connection somewhere and it is not going to be easy to locate the source. Since the auto door locks are affected, I would suggest starting on this system to find out what is missing and get to the cause which should be related to the other problems.