198002889 - 5040DD AQS POLLUTION SENSOR SIGNAL CHECK (Automatic air conditioning)

With the Examiner in voltmeter mode, select 20 Volts full scale deflection and 200 milliseconds base timeConnect the black probe of an Examiner to the vehicle earth and the red probe to pin 3 of the air quality sensor output signal    See K064 EXHAUST GAS PRESENCE SENSORTurn the key to the MAR positionWait about 36 secs for the sensor to warm up.Spray the gas in the canister (part no. 71715571) in less than 60 seconds.Press the START button.The signal shown should be a set of PWM impulses with a frequency of 100 Hz and a Duty Cycle that varies between 15 and 70% as indicated in the table below.PWM% Duty Cycle = T1 / T2 where:· T1= duration of impulse·T2 = 1/f = 1/100 Hz = Duratation of transmissionPin out:· 1. +CH/15· 2. earth· 3. output signalPWM signal meaning5% short circuit to earth of signal line15% non polluted air circulation30% level 1 pollution50% level 2 pollution70% level 3 pollution>90% short circuit +12 signal line