El mando ya no funciona porque no tiene pilas.

Here el mando means the remote control, especially in Spain. Very often people shorten el mando a distancia to simply el mando.

Be aware that mando can mean other things in other contexts, such as command, control, or even a person in charge. So the meaning depends on context.

In this sentence, because of funciona and pilas, it clearly means remote control.

Spanish usually uses the definite article more often than English. So where English might say the remote or sometimes just remote, Spanish normally says el mando.

The article el is there because mando is a masculine singular noun:

• el mando
• los mandos

Ya no means no longer or not anymore.

So:

• ya no funciona = it no longer works / it doesn’t work anymore

This is a very common structure in Spanish:

• ya no vivo allí = I don’t live there anymore
• ya no quiero café = I don’t want coffee anymore

The order is important: ya no + verb.

In Spanish, funcionar is the normal verb for machines, devices, systems, and things that work in the sense of operate.

So:

• El mando funciona = The remote works
• Mi móvil no funciona = My phone isn’t working

Trabajar means to work in the sense of doing a job, so it is used for people:

• Trabajo en Madrid = I work in Madrid

You would not normally say el mando trabaja.

Spanish often leaves out subject pronouns because the verb form already tells you the person and number.

Here:

• tiene = it has / he has / she has

The subject is understood from context. In this sentence, no tiene pilas refers back to el mando.

So Spanish prefers:

• El mando ya no funciona porque no tiene pilas.

Instead of:

• El mando ya no funciona porque él no tiene pilas.

Using él here would sound unnecessary or odd unless you were emphasizing the subject.

This is a very common question.

• porque = because
• por qué = why

So in your sentence:

• ...porque no tiene pilas = ...because it has no batteries

Compare:

• ¿Por qué no funciona el mando? = Why doesn’t the remote work?
• No funciona porque no tiene pilas. = It doesn’t work because it has no batteries.

Spanish usually does not need a separate word for any in sentences like this.

• no tiene pilas literally = it does not have batteries
• natural English = it doesn’t have any batteries

That is a normal difference between the two languages. The negative no already does the job.

Because remote controls typically use more than one battery, so Spanish naturally says pilas in the plural.

• pila = battery
• pilas = batteries

If it only needed one battery, you could say:

• no tiene pila

In everyday Spanish, pilas is the normal word for small household batteries, especially in Spain.

Sometimes, but pilas is the most natural choice here in Spain for the batteries inside a remote control.

Very roughly:

• pila often refers to small replaceable batteries
• batería can refer to a battery pack, a larger battery, or is used more broadly in some varieties of Spanish

For a TV remote in Spain, pilas is exactly what most people would say.

Because Spanish, like English, uses the present tense for things that are true right now.

• funciona = works / is working
• tiene = has

So the sentence describes the current situation:

• The remote isn’t working because it doesn’t have batteries.

Spanish does not need a special progressive form here.

Yes. There is a small difference.

• no funciona = it doesn’t work
• ya no funciona = it doesn’t work anymore / it no longer works

Ya no suggests a change from before. It implies that it used to work, but now it doesn’t.

Not in this sentence.

The verb tiene could in theory mean he/she/it has, but context decides the subject. Here the nearest logical subject is el mando, so the meaning is because it has no batteries.

If you wanted to say because you don’t have batteries, you would say:

• porque no tienes pilas

This version is the most natural and neutral:

• El mando ya no funciona porque no tiene pilas.

You can change the order a little for emphasis, for example:

• Porque no tiene pilas, el mando ya no funciona.

That is grammatically fine, but it sounds more marked or explanatory. For everyday speech, the original order is the best choice.

Yes, absolutely.

• El mando no funciona porque no tiene pilas = The remote doesn’t work because it has no batteries
• El mando ya no funciona porque no tiene pilas = The remote no longer works / doesn’t work anymore because it has no batteries

So ya adds the idea that this is a change from an earlier state.