Le centre de contrôle technique signale que ce véhicule pollue trop.

Because centre is a masculine noun in French: le centre.

This is a good reminder that French noun gender is not always predictable from the spelling. Even though centre ends in -e, it is still masculine.

It means a technical inspection center or vehicle inspection center.

In many contexts, contrôle technique refers to the official roadworthiness inspection for a vehicle, similar to an MOT or vehicle inspection depending on the country. So the full phrase is basically the place that carries out that inspection.

Here, de links nouns together in a descriptive way:

• un centre de contrôle technique
• literally: a center of technical inspection
• more naturally: a technical inspection center

French often uses de where English uses a noun as an adjective. Compare:

• une salle de classe = a classroom
• un contrôle de police = a police check

If you said du contrôle technique, it would sound more like some of the technical inspection or about the technical inspection, which is not the structure needed here.

Signale is the present tense of signaler, meaning to report, to indicate, to point out, or to flag.

So:

• Le centre ... signale que ...
• The center reports/indicates that ...

The word que means that and introduces the next clause:

• signale que ce véhicule pollue trop
• reports that this vehicle pollutes too much

In English, that is sometimes optional, but in French que is normally required here.

Because véhicule begins with a consonant sound.

French uses:

• ce before masculine singular nouns starting with a consonant sound
• cet before masculine singular nouns starting with a vowel sound or mute h

So:

• ce véhicule
• ce garage
• but cet avion
• cet homme

Since véhicule starts with v, you use ce.

Pollue is the third person singular present form of polluer:

• je pollue
• tu pollues
• il/elle/on pollue

Here the subject is ce véhicule, which is third person singular, so the verb is pollue.

Even though the spelling ends in -ue, it is pronounced like one syllable: roughly po-lyu.

French often uses the present tense in the same situations where English does:

• Le centre ... signale = The center reports / is reporting
• ce véhicule pollue trop = this vehicle pollutes too much / is polluting too much

The French present can cover both a general statement and a current assessment, depending on context. English sometimes prefers is polluting too much, but French simply uses the present: pollue trop.

Here trop means too much.

It modifies the verb pollue, so:

• pollue trop = pollutes too much

French adverbs often come after the verb, so this word order is normal.

Compare:

• Il parle bien. = He speaks well.
• Elle travaille trop. = She works too much.

So ce véhicule pollue trop is the natural French order.

Yes. Signaler can mean:

• to report
• to point out
• to indicate
• to flag

In this sentence, it suggests that the inspection center is formally noting or indicating a problem. So depending on context, English translations like reports, states, or flags that could all work.

Véhicule is more general and more formal than voiture.

• voiture = car
• véhicule = vehicle

An inspection center or official document often uses véhicule because it can refer to a car, van, truck, or another road vehicle. It sounds more administrative and technical.

A careful approximate pronunciation is:

luh sahntr duh kohn-trohl tek-neek seen-yal kuh suh vay-ee-kewl پو-lyoo trop

A few useful points:

• Le is usually a light luh
• centre has a nasal vowel: sahntr
• contrôle has a long o sound
• technique sounds like tek-neek
• signale is pronounced roughly seen-yal
• que is a short kuh
• véhicule is roughly vay-ee-kewl
• pollue sounds like po-lyu
• trop ends with a clear o sound; the p is normally not pronounced strongly in connected speech

Not especially; it follows a very standard French pattern:

• Le centre de contrôle technique = subject
• signale = main verb
• que = introduces a subordinate clause
• ce véhicule = subject of the subordinate clause
• pollue = verb
• trop = adverb

So the structure is:

[Subject] + [verb] + que + [new subject] + [verb] + [adverb]

That is a very common pattern in French and worth learning well.