323001951 - 5040BC CHECK ON COMPRESSOR ACTIVATION/DEACTIVATION BY LINEAR SENSOR (Automatic air conditioning)

Disconnect the electrical connection for the linear sensor.    See K120 LINEAR SENSOR FOR FANS Check that Pin 1 is earthed and that Pin 2 is at +5V. Connect a linear potentiometer (with an end of scale at 1 kOhm, previously positioned at around 500 Ohm between the middle pin and one of the side ones) to the pins of the electrical connector for the linear sensor. Turn the ignition key ON. Using a multimeter, check that the voltage between Pins 1 and 3 is about 2.5 V. Switch on the engine and turn the air conditioning on, using the dedicated switch located on the climate control system control unit. In these conditions the climate control system should come on normally. Alter the resistance of the potentiometer until the voltage on the multimeter between Pins 1 and 3 is around 0 V. In these conditions the air conditioning should switch off since the engine management node receives information concerning low pressure in the circuit. Alter the resistance of the potentiometer until the reading on the multimeter between Pins 1 and 3 is about 4.6 V. In these conditions the air conditioning system should switch off because the engine management node receives information concerning high pressure in the circuit.