I have a Honda Accord 2004. Sometimes when starting the car in the morning the speedometer will not work and also the gear will not change. At the same time the engine malfunction light will be on.
After driving the car for 4 – 5 minutes the speedometer will start to work. Now I will switch off the car and restart the car and everything will be perfect.
This problem is happening may monthly once or twice.
Please help me if you have any answer.

Have you had somewhere like AutoZone see if there are any codes? The will be stored for a certain amount of time, even after the light goes out. It is a good service they offer, though they are usually not well enough trained to make a proper diagnosis. I would bet that it is a speed sensor not working properly, or maybe a low fluid level. Honda automatics are an odd duck compaired to most. Unless someone has some experience with them, they probably are not going to give the right advice. But, they all have speed sensors to know when to shift. Where they are is a Honda expert's question. Again, AutoZone may be able to tell you. They do have component locations

Replace the Variable Speed Sensor (VSS), located on top of the transmission close to the firewall.