AIR CONDITIONING - Functional description

Two-zone climate control system

Functional description

Climate control control unit M70 is supplied when the ignition is turned on (INT) at pin 39 by the line protected by fuse F49 of underfacia junction unit B2.; it is supplied directly at pin 30 from a line protected by fuse F39 of underfacia control unit B2.

Pin 40 of M70 is earthed.

The control unit M70 is connected, via the CAN line, from pins 1 and 2 to the Body Computer M1 and to other nodes.

Sensors K111 (right lower treated air) and K113 (left lower treated air), K110 (right upper treated air) and K112 (left upper treated air) are connected to control unit M70: these sensors receive a reference earth from pin 11 and send signals to pins 20, 17, 9 and 18 of M70.

The frost sensor K86 receives a reference earth from pin 11 and sends a signal to pin 8 of M70.

The solar ray sensor K90 informs the control unit of the heat coming from rays: it receives a 5V supply from pin 7 control unit M70 and gives out two signals: to pin 19 for the right area and to pin 10 for the left area.

The air conditioning system is equipped with one recirculation actuator ( N82 ), two air blending actuators (N78 and N79) and two air districution actuators ( N80 and N83 ).

The recirculation actuator N82 is operated by the control unit M70 from pins 12 and 22.

The blend actuators N78 and N79 are operated by the control unit M70 by pins 32-37 and 35-24, respectively, receiving the supply for controlling the potentiometer from pin 31 of M70, a reference earth from pin 11 of M70 and sending a feedback signal to pins 25 and 26 of M70.

The distribution actuators N83 and N80 are operated by the control unit M70 by pins 33-34 and 36-38, respectively, receive a supply for controlling the potentiometer from pin 31of M70, a reference earth from pin 11 of M70 and send a feedback signal to pins 27 and 28 of M70.

Fan N85 (with built-in electronic speed regulation circuit) is ignition-operated (INT/A) by a line protected by fuse F31 of underfacia control unit B2 and controlled by relay T8 and dedicated fuse F8 of engine compartment junction unit B1.

It receives an input control signal for the various speeds from the controlunit from pin 5 of M70 and returns a feedback signal to pin 29 of M70.

The outdoor temperature sensor is located on door mirror P60: the sensor is connected to the control unit on door M66 and thence, via the CAN network, to M70.

Pin 21 of M70 controls activation of the compressor See E6021 COMPRESSOR ENGAGEMENT.

The heated rear windscreen controls are connected to pins 4 and 13 of M70 See E3030 HEATED REAR WINDSCREEN AND DOOR MIRROR DEFROSTING.

The controls for the hazard warning lights are connected to pins 15 and 14 of M70 See E2020 DIRECTION INDICATORS / HAZARD WARNING LIGHTS.

Manual Air Conditioning

Functional description

Fan N85 is supplied when the ignition is switched on (INT/A) from the line protected by fuse F31 of the junction unit B2 under the facia and controlled by the relay T8 dedicated fuse F8 of the engine compartment junction unit B1.

Control knob H81 controls the fan at different speeds via regulator O30: the control signal - earth signal - varies according to knob position and crosses or does not cross the coils of regulator O30 to determine four different voltage signals for fan N85, which thus turns at 4 different speeds.

The fan N85 operates at the first speed if the button for engaging the compressor is pressed, even if the control knob H81 is in position '0' See E6021 COMPRESSOR ENGAGEMENT.