AIC (Optional Rain Sensor)
Rain sensor operation is the same as that of E38, E39 and E46.
The AIC is activated with the wiper switch in the intermittent position from ignition position 1. If the wiper switch is already in the intermittent position when the ignition is switched to position 1 or 2, AIC will not be active. When the wiper switch is moved from intermittent to OFF and back to the intermittent position, the AIC will be active again.
The BC1 sends the wiper switch position to the AIC via a K-bus telegram. The AIC controls the time interval pauses from zero to infinity depending on the wetness of the wind-shield. The AIC will transmit a K-bus message every 10 seconds when the wiper switch is on intermittent if the screen is dry (indicating that the AIC is functional), or more often if it is wet. If the BC1 does not receive this telegram for a period greater than 12 seconds, then the AIC function will be disabled and normal intermittent function adopted. A fault code is generated. If the AIC system fails, the intermittent wipe function recognized by vehicles without AIC, is employed.