198003588 - E5020 ENGINE COOLING - FUNCTIONAL DESCRIPTION (Manual Air Conditioning, Automatic air conditioning)

FUNCTIONAL DESCRIPTION

Relays T6 and T7 of the engine compartment junction unit B1 manage the switching on of the two speed fan N11: the coil power lines are protected by fuses F6 and F7 , also in engine compartment junction unit B1 .Both are energized by an earth control signal coming from the engine management control unit M10.If the engine coolant reaches an initial temperature level, or the linear sensor K120 signals to the control unit M10 - pin 57 of connector A - that a certain pressure level has been reached, then the control unit M10 sends a signal - from pin 13 of connector A - which energizes the 1st speed fan relay T6 which sends the power supply to the fan N11 via the additional resistance O10: the fan turns at the first speed (slow).The engine temperature sensor K36 receives a reference earth from pin 29 of connector B of control unit M10, and sends a signal proportional to the engine coolant temperature to pin 43 of the same control unit.The linear sensor K120 receives a power supply and reference earth from the engine management control unit M10, pin 7 and 28 of connector A.If the engine coolant temperature reaches a higher level or linear sensor K120 indicates to control unit M10 that a higher pressure level has been reached, then control unit M10 sends a signal from pin 12 of connector A to fan 2nd speed relay T7, which then sends power to fan N11 directly: the fan turns at the maximum speed.