Welcome Pagiek. For me, MN 43 does not provide a clear explanation, similar to SN 22.79, which says:
And why do you call it consciousness?
Kiñca, bhikkhave, viññāṇaṁ vadetha?
It cognizes; that’s why it’s called ‘consciousness’.
Vijānātīti kho, bhikkhave, tasmā ‘viññāṇan’ti vuccati.
And what does it cognize?
Kiñca vijānāti?
It cognizes sour, bitter, pungent, sweet, hot, mild, salty, and bland.
Ambilampi vijānāti, tittakampi vijānāti, kaṭukampi vijānāti, madhurampi vijānāti, khārikampi vijānāti, akhārikampi vijānāti, loṇikampi vijānāti, aloṇikampi vijānāti.
It cognizes; that’s why it’s called ‘consciousness’.
Vijānātīti kho, bhikkhave, tasmā ‘viññāṇan’ti vuccati.
SN 22.79
Possibly we can compare it to perception (sanna), described as:
And why do you call it perception?
Kiñca, bhikkhave, saññaṁ vadetha?
It perceives; that’s why it’s called ‘perception’.
Sañjānātīti kho, bhikkhave, tasmā ‘saññā’ti vuccati.
And what does it perceive?
Kiñca sañjānāti?
It perceives blue, yellow, red, and white.
Nīlampi sañjānāti, pītakampi sañjānāti, lohitakampi sañjānāti, odātampi sañjānāti.
It perceives; that’s why it’s called ‘perception’.
Sañjānātīti kho, bhikkhave, tasmā ‘saññā’ti vuccati.
MN 43; SN 22.79
While not clear sutta explanations, my mere guess is MN 43 & SN 22.79 are describing consciousness as ‘sensory impact’, using ‘impacting’ experiences such as ‘pleasure’, ‘pain’, ‘neutral’, ‘sour’, ‘bitter’, ‘pungent’, ‘sweet’, ‘hot’, ‘mild’, ‘salty’ and ‘bland’.
Where as ‘sanna/perception’ is more ‘descriptive/labelling’, using examples of ‘blue, yellow, red and white’.
However, as i said, I am only guessing. 