Abstract: Method for transmitting data from a plurality of slave terminals (TE1, TE2, TE3, TE4) to a master terminal (TM) via a communication bus (10). According to the invention, said method includes the following steps: (a) the master terminal (TM) transmits a check sequence (SCi) including a response sequence (SRi), intended to receive, from the slave terminals (TE1, TE2, TE3, TE4), an indicator of the presence of data to be transmitted, (b) the slave terminals provide said presence indicator in said response sequence (SRi), (c) the master terminal (TM) provides a data transmission authorization (SA) to a slave terminal of which the indicator of the presence of data to be transmitted is positive, (d) said slave terminal transmits said data after receiving the authorization from the master terminal, (e) steps (c) and (d) are repeated for any slave terminal of which the indicator of the presence of data to be transmitted is positive. Application to motor vehicle air conditioning systems.