42OperationIndicator field(Fig. 19/1) The indicator field enablesthe scrubber drier to provide feedbackon the operating status of the vehicle.This only relates to operating stateswhich cannot be switched on and off viathe operating panel: recovery tank full,parking brake applied and error mes-sage.The individual buttons and functions aredescribed in detail below:Indicator for recovery tankmaximum fill level(Fig. 19/2) The yellow controllamp lights up when the recov-ery tank has reached its maxi-mum fill level. Also, a "beep" signal isissued every 15 seconds. In this case, afloat switch switches the suction turbineoff and the squeegee is raised.Indicator for parking brakeapplied(Fig. 19/3) The control lamplights up red when the parkingbrake has been actuated viathe pedal to the left of the steering col-umn. If the traction drive is switched on,an acoustic signal is also issued.Indicator for function faults(Fig. 19/4)The control lamp lights up redwhen one of the followingfaults occurs:• The thermostatic switch disconnectsfrom the brush or hydraulic motor.• One of the safety fuses is defectiveor an electronic fuse has beentripped.• Another fault has occurred.At the same time, a four-digit code ap-pears in the display of the service indi-cator (Fig. 19/5). This error code inferswhich fault has occurred (refer to Sec-tion 3.5.1). At the same time, the controllamps flash and an acoustic, pulsatingsignal is issued.